Aids to marine navigation of the United States

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Material Information

Title:
Aids to marine navigation of the United States
Physical Description:
iv, 35 p. : illus. (part. col.) ; 23 cm.
Language:
English
Creator:
United States -- Coast Guard
Publisher:
U.S. Govt. Print Off.
Place of Publication:
Washington
Publication Date:
Edition:
Rev. June 1965.

Subjects

Subjects / Keywords:
Aids to navigation -- United States   ( lcsh )
Genre:
non-fiction   ( marcgt )

Notes

General Note:
"CG-193."

Record Information

Source Institution:
University of Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 005012926
oclc - 08985068
lccn - 65061486
Classification:
lcc - HJ6645 .A52 1965
System ID:
AA00012242:00001


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CG-193


AIDS TO MARINE NAVIGATION




OF THE UNITED STATES


TREASURY DEPARTMENT

UNITED STATES COAST GUARD












































Digitized by the Internet Archive
in 2012 with funding from
University of Florida, George A. Smathers Libraries with support from LYRASIS and the Sloan Foundation


http://www.archive.org/details/aidstomarinenavi00unit





UNITED STATES COAST GUARD


Revised June 1 965
CG-1 93











U.S. GOVERNMENT PRINTING OFFICE
WASHINGTON : 1965


AIDS TO MARINE NAVIGATION

OF THE UNITED STATES































CONTENTS
Page
]Foreword,,_____________ '
Purpose of aids to navigation __ ____ _________ 1
Lighthouses.______________ 1
Range Hights_______ _________ _-------- _
Lightshipe_______________
Fog signals______ _________ ____________ __ 10
]Electronic aids to navigation_____ __________ ______ 11
Buoys__ ____ __________ _________ ____ 17
Daybeacons__________________-____ 23
Intracoastal Waterway. __________ __ ______ ____ 23
Syrabols employed upon charts_ ________ _________ 26
Lists of Lights andl Other Marine Aids ___ _______--------- 26
Notice to Marinems_-l____ ___-______ ___ ___ ___ ___ 27
Early history________ ____ ____________ 30
Jurisdliction______ ___-__________ __________ _____ 31
Related nautical publications____ ____,____ _________ 32




















Th']e purpose of this publication is to acquaint those whoe are inter-
ested in. the study of the science of navigation with the basic prin-
ciples underlying the marking of coasts and waterways of thne United
States and its possessions with lighthouses, lightships, fog signals,
radiiobeacons, 10ran, and buoys. It explains briefly the significance
of the various colors of lighthouses and buoys, of the wide variety of
light and fog signal characteristics, and of the system of electronic
aids to navigation. It states in simple terms the manner in. which the
information provided by these aids is applied in actual navigation.
The text treats primarily wiith the manner1~1 in which the physical
characteristics of the various aids to navigation serve the mariner.
Engineering problems connected with the construction and mainte-
nance of the aids to navigation are not discussed, nor is the publication
intended to replace the Light List, Coast Pilots, and other Govern-
ment publications which should1I be at hand during actual navigation.


FOREWORD







DEFINITION

The expression "'Aids to Navigation" as used herein, includes light-
houses, lightships, radiobeacons, loran, fog signals, buoys, minor lights,
and daybeacons.

THE PURPOSE OF AIDS TO NAVIGATION

Aids to navigation are placed at various points along the N;ation's
coasts and navigable w;te~r~ways as markers and guides to enable marin-
nerss to determine their position with relation to the land and to
hlidden. dangers. Within the bounds of actual necessity and reasonable
cost, each and every aid is designed to be seen, or heard over the greatest
practicable area.
Aids to navigation assist maariners in making landfalls when ap-
proaching from, overseas, mark isolated dangers, make it possible for
vessels to follow the natural and imaproved channels, and provide a con-
tinuous chain. of charted marks for coast piloting.
As all aids to navigation serve the same general purpose, such
structural differences as those between an unlighted buoy and a light-
ship, or a lighthouse and a radiobeacon, are solely for the purpose of
meeting the conditions and requirements of the particular location at
which the aid is to be established.

LIGHTHOUSES

Lighthouses are found upon all coasts of the United States, upon
the Great Lakes, and along some of the interior waterways of the
country. Such structures are so well known as to require little
description. ILighthouses are placed where they will be of mnost
use, on prominent headlands, at entrances, on isolated dangers, or
at other points where it is necessary that mariners be warned or
guided. Their principal purpose is to support a light at a consid-
erable height above the water. The same structure may also house a
fog signal and radiobeacon equipment, and also contain quarters for
the keepers. However, in th~e majority of instances, the fog signal,
the radiobeacon equipment, and the operating personnel are housed
in separate buildings grouped around the towPer. Such a group of
buildings constitutes a light station.


GEN ERAL




2 AIDS TO MARINE: NAVIGATION OF THE UNITED STATES

TYP I CAL IG HT STRU CTU RE S


CYUINDRICAL TOWER SQUARE
HOUSE ON CYUNDRICAL BASE


MASONRY STRUCTURE


OFFSHORE LIGHT STRUCTURE


SKELETON IRON STRUCTURE





AIDS TO MARINE: NAVIGATION OF TH-E UNITED STATES Fj

TIhe location of a lighthouse, whether in. the water or on, shore,
the importance of the light, the kind of soil upon which it is to
be built, and the prevalence of violent storms, have a direct bearing
upon the type of structure erected and on the materials of which. it
wciill be built. 1Engineering problems will not be entered into here,
but it is important to note that the materials used and types of con-
struction differentiate one lighthouse from another and hence aid in
identification.
Lighthouses vary markedly in, their outward appearance because
of the points already mentioned and also because of the great dif-
ference in the distances to which their lights should be seen. Where
the need for a powerful light is great and the importance and density
of traffic warrants, a tall tower with a light of high candlepower is
erected. Conversely, at points intermediate to the major lights, where
the traffic is light, and where long range is not so necessary, a less
expensive structure of more modest dimensions suffices.
The terms, secondary lights, minor lights, and automatic lights
indicate in a general way a wide variety of lights, each. class shading
imperceptibly into the next. These lights may be displayed from
towers resembling the important seacoast lighthouses, or mary be
shown from almost any type of inexpensive structure. The essen-
tials of a light structure where keepers are not in residence as for
all11ights, are: best possible location dependent on physical conditions
of the site, sufficient height for the location, a rugged support for the
lantern, and a housing for the tanks of compressed gas or electric
batteries from which the light is operated. Meeting these essentials
are many types of structures--mall tank houses surmounted by a
short skeleton tower, a cluster of piles supporting a battery box and
the lens, and countless other forms.
At thie present time many of the lighthouses which were originally cared for
by resident keepers are operated automatically, because of the availability of
commercial electric current. There are also now a great man~y automatic lights
on inexpensive structures, cared for through periodic visits of Coast Guard cutters
or of attendants placed in charge of a group of such aids.
The recent introduction of much new automatic apparatus means that the
relative importance of lights cannot be judged on the basis of whether or not
they have resident keepers, for a number of powerful lights in towers of great
height are now operated without continuous attention.

COLORING OF STRUCTURES

Color is applied to lighthouses and automatic light structures for
the purpose of making them readily distinguishable from the back-
ground against wcchich they are seen, and to distinguish one structure





4 AIDS TO MARINE NAVIGATION OF THE: UNITED STATES

COLORING oc TyplCAL LIGHTHOUSES


__


_ _~~_ __~


ST. AUGUSTINE FLA.


BOSTO N, MAS S.


CAPE HENRY, VA.


TYBEE, GA.




AIDS TO ]MARINE NAVIGATION OF THEE: UNITED STATES


from others in the same general vicinity. Solid colors, bands of color,
and various other patterns are applied for these purposes.
Minor light structures are sometimes painted black or red, to indi-
cate the sides of the channel which they mark, following the sam~e
lateral system used in the coloring of buoy~s. When. so painted, red
structures markr the right side of th~e channel, anrd black structures the
left side of the channel, entering from se~award.

LIGHT CHARACTERISTICS

Lights are~given distinctive characteristics so that one light mtay
be distinguished from another, or as a means of conveying certain
definite information. This distinctiveness is obtained by employing
lights of various colors, by having lights that burn steadily, and
others that flash at intervals of great variety. The principal "charac-
teristics" employed for aids to navigation are shown on page 6.

COLORS

The three standard light colors used for lighted aids to navigation
are white, red, and green.

LENGTH OF LIGHT PERIODS

By varying the length, of the periods of light and darkness of any
of the flashing or occulting characteristics, a great variety of charac-
teristics may be obtained. Advantage: is taken of this to secure the
necessary distinctiveness between aids of a given area.

IDENTIFICATION OF LIGHTS

When making a landfall, the charts and the "Lists of L~ights and
Other Marine Aids"' commonly called light lists should be consulted
to learn the exact, characteristics of the light or lights which it is
expected will be first seen. When a light is observed, its color is
noted and, by means of a watch or clock: with a second hand, a note
is made of the time required for the light to perform its full cycle
of changes. If color, cycle, and number of flashes per cycle agree
w-ith the information in the light list, correct identification has been
made. The light list should be examined to ascertain, if any other
light in the general locality might be seen. and mistaken for the
desired light. If there is doubt, a careful timing of the length of
all flashes and dark intervals, for comparison with the light list,
is usually conclusive.






) AIDS TO MARINE NAVIGATION OF THE UNITED STATES

CHARACTERISTIC LIGHIT HIABSS


Symabols and mewaning

Illustration Lights which Lights which Phase description
do not change show color
color v ariations


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group flash-
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A continuous etead
light.
A fixed light varied
at regular inter-
rale by a flash of
Sweater brilliance.
A fixed light varied

more flashes of
greater brilliance.


intervals, the
duration of lighlt
always being less
than the duration
of darkness.


of 2 or more flashes

ILight fldashe ar
""?mdgrups a t-
different numbers.
Light in which dfashes
tion are grouped
in such a manner as
to produce a Morse
character or char-
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6ov nathlesper mn-
ute.
Shove quick flashes
l:1l:"". by a dark
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darknese equal.
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eclipsed at regular
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tion of light always
greater than the
duration of darkness
A lightords r a ss
at regular intervals



nate groups of
different numbers.


Alt.Occ. *
Alternting
occulting.





AIDS TO MARINE NAVIGATION OF THE UNITED STATES


HOWV FLASHES ARE PRODUCED

The flashing lights of lighthouses and minor lights are produced in several w~ays.
In somze of the larger lights the flashes result from the rotation of the lenses
in which various flash panels are incorporated. The use of electricity as the
illuminant has also made it possible to produce flashes by moeans of timing devices
which interrupt the flow of current or conceal the light source at definite
latervals.
]Electricity is the illuminant now used in all of the larger lighthouses. ]Electric
incandescent lamps placed inside the larger sizes of lenses or reflectors produce
beams of as much as 14,000,000 candlepower where such intensity is required.
Lenses, which are aggregates of highly polished glass prisms, are assembled in
a variety of typ~cs to produce the characteristics desired.

VISIBILITY OF LIGHTS

The theoretical visibility of a light in clear weather depends upon
two factors, the height of the light above water, and its intensity. The
height controls what i-s known as the geographic range, while thle
intensity controls what is known as the luminous range.
As a rule, for the principal lights the luminous range is greater
than the geographic, and the distance from which, such lights are
visible is limited by the earth's curvature only. Under some atmos-
pheric conditions the glare or loom of these lights, and occasionally
the light itself, may be visible far beyond the computed geographic
range. On the other hand, and unfortunately more frequently, these
distances may be lessened by fog, rain, snow, haze, or smoke.
Lights on inland waters, where their radius of usefulness is not
great, are frequently of insufficient intensity- to reach to the full limit
of their geographic range.

SECTORS

Sectors of colored glass are placed in the lanterns of certain light-
houses to mark shoals or to warn mariners off the nearby land. Lights
so equipped show one color from most directions and a different
color or colors over definite arcs of the horizon in jicated in thne light
lists and upon the charts. A sector changes the color of a light,
when viewed from certain directions, but not the characteristic. For
example, a flashing white light having a red sector, when ~viewed from
within the sector, will appear flashing red.





8 AIDS TO MARINE NAVIGATION OF TH~E UNITED STATES

Sectors may be but a few degrees in width, marking an isolated
rock or shoal, or of such. widthn as to extend from the direction of the
deep water toward shore. Bearings referring to sectors are exrpressed
in degrees as observed from a vessel toward the light.
In the majority of cases, water areas covered by red sectors should
be avoided, the exract extent of the danger being determined from
an examination of the charts. I~n some cases a narrow sector may
mark the best water across a shoal. A narrow sector may also mark
a turning point in a, channel.

FOG SIGNALS

These signals form an important part of the equipment of many
lighnthouses situated in sections of the country where fog or low
visibility is prevalent. Identification is made in the same maanner
as with lights. Each fog signal station is assigned a signal consisting
of a definite number of blasts recurring at stated intervals. The
sound or tone of the signal varying wocith the type of mechanism
employed, also assists in identification. Fog signals are treated in
greater detail on page 10.

RANGE LIGHTS
Two lights, located some distance apart, visible usually in. one
direction only, are known as range lights. TIhey are so located that
th~e mariner by bringing his ship into line with them, when they
will appear one over the other, places his ship on the axis of the
channel. If he steers his ship so that the lights remain continuously
in line, he will remain wPithin the confines of the channel. Entrance
channels are frequently marked by range? lights. The Delaware River
and the St. Johns Rtiver on the Atlantic coast, and the Columbia
River on the Pacific coast are examples of successive straight reaches
marked in this manner.
The lights of ranges may be any of the three standard colors, and
mnay also be fixed, flashing, or occulting, the principal requirement
being that they stand out distinctly from their surroundings. 1\ost
range lights lose brilliance rapidly as a ship diverges from. the range
line. Ranges should be used only after a careful examination of the
charts, and it is particularly important to determine for what dis-
tance thne range line can be safely followed, this information not
being obtainable from thne lights themselves in. all cases.





AIDS TO MARINE NAVIGATION OF THE UNITED STATES


LIGHTSHIPS

Lightships serve the samle purpose as lighthouses~r, being equipped
with lights, fog signals, andt radiobenelconls. They take thle fotrm of
ships only because they ar~e pl;wedt at points where it w\ouldl be imi-
practicable to build lighthouses. Ltightshipls mark thle entrances to
important h~arbor~s or estuarieis, (IangerIouIs sh1oals lyinlg in murchl fr~e-
qurenlted waters, and~ also serve as leading~ mrnlks for both tranllsoceanic
and c~oast wise traffic.
COLOR OF LIGHTSHIPS
All lighltshlips in United States water~s, except Lake Hulron Lighlt-
ship, are painted red with~ thle name of the station in whlite onl both
sides. Lake Huiron Lightship is painted black w\ith the niame of the
station painted in white on both side t. Superstar ucc t urlesi are white;
masts, lantern galleries, ventilators, andi stacks are paintedl buff. Re-
lief lightships are painted the same color as the regular station ships,
wIith the word "LRELIEF"` ) in white letters on the sidles.

RELIEF LIGHTSHIPS

These may be placed at any of the lighltship> stations, and, when
practicable, will exhibit lights and sound signals having the char-
acteristics of the station. Relief ships m~ay differ inl outwardly ap-
pearance from the regular station ships inl certainly min~or details.

SIGNALS
The masthead lights, the f(,g signals, andc th~e radiobeacon sign-als
of lightships all have definite characteristics, so that each lighltship
mnay~ be distinguishled from others and also froml nearby lighthouses.
Ais with lighthouses, details regarding these signals are shown briefly
on charts and more completely in the light lists.
A lightship under way or off station will fly the International
Code signal flags "PC" signifying lightship is not at anchor on her
station. It will not show or sound any of the signals of a lightship,
but will display the lights prescribed by the International or Inland
Rules for a vessel of its class. While on station a. lightship shows only
the masthead light and a less brilliant light on the forestay, the latter
serving to indicate the direction in w-hich the ship is headling. By
day the lightship will display the International Code signal of the
station, whenever it appears that an approachinlg vessel does not
recognize the lightship or requests the information. As lightships
ride to a single anchor, the light on the forestaiy also indicates the
direction of the current.





10 AIDS TO MARINE NAVIGATION OF THIE UNITED STATES

POWER PLANTS

United States lightships are self-propelled vessels capable of pro-
ceeding to and from their stations under their o~wn power. By this
means they also workr back to their stations if driven off by storms,
and also use their engines to relieve the strain on their moorings in
severe wFpeather. Most lightships are D~iesel propelled, some direct
connected, others with geared drive, and still others with an electric
motor connected to the propeller shaft and served by Diesel electric
generating sets. A few ships still employ reciprocating steam engines,
with oil-fired boilers.
Most lightships, when on station, derive power for the operation
of their signals from Diesel driven. auxiliaries. In the D~iesel-electric
ships, one or more generating sets are used for auxiliary purposes in
accordance with the demand for power.
The names appearing on the sides of lightships are the names of the stations
which the ships occupy at the time. Individual ships of the service are identified
by permanent numbers. During a lifetime of 40 or 50 years a lightship may
occupy a half-dozen stations, having the name of each in turn painted upon it.

FOG SIGNALS
Any sound-producing instrument operated in time of fog from a
definite point shown on the charts, such as a lighthouse, lightship, or
buoy, serves as a useful fog signal. To be effective as an aid to naviga-
tion, a, mariner must be able to identify it and to know from what
point it is sounded. The simpler fog signals are bells and whistles on.
buoys. As such signals on buoys which are operated by the action of
the sea do not produce sounds on a regular time schedule, positive
identification is not always possible.
At all lighthouses and lightships equipped with fog signals, these
signals are operated by mechanical or electrical means and are sounded
on definite time schedules during periods of low visibility providing
the desirable feature of positive identification.
TIhe various types of apparatus employed for sounding fog signals
are of interest to the mariner principally because each type produces
distinctive sounds, familiarity with which assists in identification.

SIGNAL CHARACTERISTICS

These are composed of blasts and silent periods. A definite time is
required for each signal to perform a, complete cycle of changes.
This time, stated in the light list is one of the means of identification.
Where the number of blasts and the total time for a signal to complete
a cycle is not sufficient for positive identification, reference may be




AIDS TO MARINE NAVIGATION OF TH-E: UNITED STATES 11

made to details in the light list regarding the exact lenlgthl of each
blast and silent in~tervazl.
The various types of fog7 signals differ in tone, and this facilitaztesttt~~~
the recognition of the re~spectivre stations. Tlhe type of fog signal
apparatus for each station is stated in the light lists.
DIiaphones produce sound by means of a slotted reciprocating piston
actuated by compressed air. Blasts may consist of two tones of dif-
ferent pitch, in which case the first part of the blast is high and the
last of a low pitch. These alternate-pitch signals are called "Ltwo-
tone."
Diaphragm horns produce sound by means of a disc diaphragm
vi'bra~ted by compressed air or electricity. Duplexr or triplex horn
units of differing pitch produce a chime signal.
Reed horns produce sound by mea~ns of a steel reed vibrated by
compressed air.
Sirens produce sound by means of either a disc or a cup-shaped
rotor actuated by compressed air, steam, or electricity.
Whistles produce sound by compressed air emitted through at cir-
cumferential slot into a cylindrical bell chamber.
Bells are sounded by means of a hammer actuated by a descending
weight, compressed gas, or electricity.

ELECTRONIC AIDS TO NAVIGATION

MARITIME RADIOBEACONS
As the first electronic system of navigation, radiobeacons provided
offshore coverage and became the first all-weather electronic naviga-
tional aid. Since the first installations in 1921, the number of marine
radiobeacons has increased to the extent that the frequency band
assigned for their use, 285 to 325 kilocycles, has become very congested.
In 1963 the Coast Guard operated 189 radiobeacons located on. the
Atlantic and G~ulf Coasts, on the Pacific Coast and on the Great Lakes.
TIhese radiobeacons are located at lighthouses, on lightships and on
shore, all positions being charted.
In order to use this system, the mariner needs a, radio direction
finder, which is a specially designed radio receiver with a directional
antenna. This receiver is used to determine the direction of the signal
being emitted by the shore station, relative to his vessel.
TIhe basic value of the ratdiobeacon system lies in its simplicity of
operation and its relatively low cost even though the results obtained
may be somewhat limited. The general problems and practices of
navigation. wFhen. using radiobeacons are very similar to those en-
counterep when using visual bearings of lighthouses or other charted
objects.
A radiobeacon is basically a short-to-medium range (up to 100





1f2 AIDS TO MARINE NAVIGATION OF THE UNITED STATES

miles) aid. Although bearings can be obtained at greater ranges,
they will be of doubtful accuracy and should be used with caution.
When the distance to a radiobeacon is greater than 50 miles, a correc-
tion should usually be applied to the bearing before plotting on a
mercator chart. These corrections, as well as information on accuracy
of bearings, plotting anmd other maatters, are contained in United States
Navy Oceanographic Office publication HE.O. 117 (Radio Niavigational
Aids) .
T'he majority of Coast Guard radiobeacons nowC transmit signals
for 1 minute out of every 6 minutes regardless of weather conditions,
but some radiobeacons transmit their signals continuously. Miarker-
beacons are low-power continuously operating radiobeacons for local
use only, and are used primarily as horning beacons to harbor areas.
Since markerbeacons do not have identifying characteristics, identifi-
cation. is made by operating frequency and their continuous operation.
T~he characteristic identifiers assigned to marine radiobeacons in
this country have been limited to a brief and simple combination of
dots and dashes much. like our lights along the coast, except that radio-
beacons have a 10-second dash at the end of their operating minute to
allow a mariner to refine his bearing. Also, the identifying signal
of all marine radiobeacons is superimposed on. a continuous carrier
to fatcilititate their use by navigators having automatic direction
finders.
The accuracy to be expected from the system depends to a large
extent on the skill of the operator, the condition and type of equip-
ment being used, and the accuracy of the ship's calibration curve.
Marine radiobeacon installations are sited for the purpose of providing
the required coverage to the mariner and are service-arc calibrated to
assure that excessive errors do not exist in thne shore installation. The
Coast Gruard operates special calibration beacons for use by the
mariner. A comparison of visual beatrings with the radio bearings,
will determine what, if any, errors exist in the shnipboard installation.
These calibration beacons transmit either continuously during sched-
uled hours or upon request, as indicated in station details conrtained in
the Lig~ht List.
T'he range at which a particular marine radiobeacon will be heard
depends on atmospheric conditions and on the sensitivity of the re-
ceiver being used. The advertised service range of marine radio-
beacons is expressed in miles; nautical miles for the Atlantic, Gulf and
Pacific Coasts, and statute miles for the Great Lakes. The signal
strength available at the service range designated for a radiobeacon
varies with the latitude of the radiobeacon station, being highest in
the southern latitudes where the atmospheric noise level is also highest.
The United States marine radiobeacon. system is adjusted to th~e
belowFP listed field strength values at the limits of each radiobeacon's




AIDS TO MARINE NAVIGATION OF TH~E UNITED) STATES 13

advertised service range, according to the IntI it udle of the radich~encon
station :
50 microvolts per meter north of 40* North.
75 microvolts per meter between 40" North and 31* North.
100 microvolts per meter below 31" North.
It is necessary that the marine radiob~enonl system. be adj usted to these
values in order to provide a signal of su~ffiCijentf strength. for direction
finding purposes since~ thle atmospheric noise must be overcome. Ft4or
example, for three different radiobea~con t ra nsmrni t terse, each of the satme
advertised service range but with one localtedl at B-oston, one at Norfolk
antd at Ml/liamni, the signal st reng~th at the limit of its service range
would be 50 percent stronger for Norfolk compared to Boston, and
100 percent stronger for Mfiamri, again compared to BEoston. However,
the va.scble! signal is no greater for Norfolk or Miami than for Boston
since the atmospheric noise which must be overcome is much. stronger
in the Sou~th, than in the N~orth~.
In general, the better t-he sensitivity of a receiver (i.e., t~he lower the
signal strength required to obtain satisfactory bearings) the better the
receiver is for direction finding purposes. Unless the reeiv'er and
antenna combination being used by the mariner is capable of obtaining
a radio bearing on a signal as low as 50 microvolts per meter, full be~ne-
fit wCill not be obtained from the system.
]For example, a mariner using a direction finder with. a sensitivity of
50 microvolts per meter could obtain a bearing on a 50-mile radio-
bacon located near New York: at the adv\ertisedl service range of 50
miles. H-owever, if the mariner was using a direction finder with a
sensitivity of only 100 microvolts per meter he would not be able to
obtain a bearing on the same 50-mile New York radiobeacon. until he
approached to within approximately 25 miles of the radiobeacon.
station.
Thre selectivity of a receiver is important because it allows thne direc-
tion-finder to receie: a desired signal on a particular frequency while
rejecting any undesired signals which mayr be present on adjacent
frequencies.
Since the bandwidth of the transmitted radiob~eacon signal is relaz-
tively narrow, being onlyr 2.1 kilocy~cles, a narrowi-band receiver, one
having good selectivity, is well suited for direction finding purposes.
The narrow-band receiver should extract all of the useful information
from the transmitted marine radiobeacon signal.
Although a wider-band receiver may also extract all of the useful
information from the tranlsmitted signal, it will also admit more noise
and more undesired signals, if these signals are~ present on adjacent
frequencies. T1Che additional noise and undesired-signal interference
may~ reduce the usefulness of the desired signal and effectively shrink
the service range of the radiobeacon below its advertised value. This





14 AIDS TO MARINE NAVIGATION OF THE UNITED STATES

is a receiver defect, not a system error. Planning for the marine
radiobeacon system is presently based on direction-finder selectivity
specifications as followvss:
Frequency deviatioon from Approamiate signal ratios
resonant frequency DB below, resonance for rejection of undesiredl
(ko/s) response signals
:62 ...... ........ ---------- 3 1.4
-t3 .......... ... _. .------- 12 4. O
-r4 ...____________,,_ 25 17. 5
+s0 ..... ------------------- 50 300. O
+9-tO ------------- --------- ? .... 0 3000. O
-112 _. __----- -- --- 80 10, 000. O

APt present these selectivity characteristics are one of the limiting
factors in regard to the accommodation of the. required number of
marine beacons within the frequency band allocated for this use,
285 to 325 kilocycles. Therefore, it is reasonable to assume that as
more requests are received for radiobeacon coverage it wrill be neces-
sary to tighten these selectivity specifications.
Therefore, a mariner using a, direction-finder receiv-er with sufficient
sensitivity to take a satisfactory bearing on a signal of 50 microvolts
per meter and having at least the above prescribed selectivity should
obtain full benefit from, the marine radiobeacon system and should
not receive harmful interference.
Some Coast Guard ratdiobeacons are synchronized with sound fog
signals at the station for distance finding. The beginning of the
10-second radio dash and the beginning of the 5-seconnd blast of the
fog signal are synchronized for this purpose. TIhe 10-second radio
dash and the long (5-second) blast of the fog signal commence at the
same instant. Therefore, when within audible range of the sound
signal, navigators on vessels with radio receivers capable of receiving
the radiobeacon signals mazy readily determine their distance from
the station by observing the time in seconds which elapsed between
first hearing the beginning of the 10-second radio dash and the begin-
ning of the li-second sound blast and dividing the result by 5.5 for
nautical miles. The error of such observations should not exceed 10
percent.
Information regarding the location, operation and ca ut iona ry notes
on marine radiobeacons is given in the Coast Gruard Light List. In
addition to the above information, the United States Navy Oceano-
graphic Office Publicaltion H-.O. 117 entitled "Radio PNavigational
Aids," contains information on accuracy and corrections to be applied
when plotting bearings. Radiobeacon system charts which sh1ow the
general locations and operating characteristics of Coast Gruard radio-
beacons are avanilable in the various L~ight L~ists, namely, the Atlantic,
the Pacific, and the Great L~akes. These charts are suitable for posting
near the radio direction finder for ready reference.





AID)S TO MARINE: NAVIGATION OF THE UNITED) STATES 15

T'he term. "Loran" is derived by combining the first letters of the
words "long range aid to navigation." Isra~n is an electronic system by
means of which a navigator can determine position or a line of position
accurately and quickly unaffected by weather. It makes use of special
radio transmitting stations on shore (loran transmitting stations),
specially designed radio receivers with an electronic time measuring
device (10ran receiver indicator) and special charts and tables (10ran.
charts and tables).
T'he loran tralIsnsmi t ti g st actions, strategically locat ed on shore, oper-
ate in pairs. Each pair produces signals from which one line of
position may ~be determined. Pairs are further arranged in chains of
three or more stations from which two or more lines of position can
be derived thereby providing fix coverage. When the chain arrange-
ment is used, thne intermediate station operates in both. adjacent pairs.
The navigator may obtain position information from any pair, both
stations of which are within reception range of his receiver-indicator.
L[oran signals are transmitted continuously. Reliability of better
than 99 percent from each pair of stations has been the rule. T~he
loran transmissions are emitted as short bursts of radio energy recur-
ring at selected regular intervals of time. The use of pulse transmis-
sion of signals permits the identification of individual transmissions
on the same radio frequency and t~he measurement of time difference
between reception of transmissions from each station in a pair of loran
transmitting stations.
In loran, the time difference of reception of signal transmissions
from a pair of loran transmitting stations is measured electronically
and not the individual distance to the stations themselves. The mneas-
urem~ent is known as a loran reading. There are many points at wPhich
the same loran reading is obtained but all these points fall along a
smooth curve (a spherical hyperbola) called a loran line. Loran read-
ings showp as loran lines having geographic position on loran charts
or a series of loran readings can be transposed to construct 10ran lines
having geographic position by use of loran tables. It is not necessary
to know the charted locations of loran transmitting stations to use
the loran system.
The diagram of figure 1 illustrates the basic principles of the deter-
mination of position by means of 10ran. The 10ran readings can be
obtained with great accuracy, day or night, during all kinds of
weather. Calculations by the navigator in determining the lines of
position are practically mil.
There are two L~oran syVstems in use today, Loran-A (previously
known as "standard loran") and 10ran-C. Table 1 lists pertinent
characteristics of each.






16 AIDS TO MARINE: NAVIGATION OF TH-E UNITED STATES

TABLE 1

Loran-A Loran-C

Frequency...................... 3 channels in 1850 to 1950 ke. band..... 100 ke.
Approximate range............._ 700 miles day (groundwave),1400 1,200-1,500 miles groundwave.
miles night (groundwave adsy
wave) .
Time difference measurement Envelope superpositionl, manual......l Automatic, electronic, envelope
technique. (coarse) and cycle (fine).
Transmission.................... Single pulse from each station........- Multipulse.
Indication of malfunction.... ... Yes...................................I Yes.
Accuracy....~.~...~............._ I mile groundwave, 6 miles skywave, 1,500feet at 1,00 miles
most accurate near baseline;de
grades as distance between loran
lines increases, poor in baseline ex-
tension areas.
Position determiation,.......... Intersection of separate LOP from Continuous fix from chain.
each pair.


LINE OF
POSITION
DETERMINED
FROM
"A" READING




AIDS TO MARINE NAVIGATION OF THIE UNITED STATES 17

The Coast Guard maintains and operates 47 of the 80 Loran-A trans-
mitting stations now in existence. Of the 80 stations, 70 are in con-
tinuous operation. The Coast Guard maintains and operates 19 of the
24 existing Loran-C transmitting stations and 7 of the 8 Loran-C exist-
ing monitor stations. The Loran-C system is in continuous opera;tionl.
Loran charts and tables are obtainable for sale from the U.S. Navy
Oceanographic Office, Washington, D.C. 20390.

BUOYS
THE SIGNIFICANCE OF BUOYS

The primary function of buoys is to warn the mariner of some
danger, some obstruction, or change in the contours of the sea bottom,
and to delineate the channels leading to various points, so that he
mnay avoid the dangers and continue his course safely. TLhe utmost
advantage is obtained from buoys when they are considered as marrk-
ing definitely identified spots, for if a mariner knows his precise loca-
tion at the moment and is properly equipped withn charts, he can plot
a safe course on which. to proceed. Such. features as size, shape,
coloring, numbering, and signaling equipment of buoys are but means
to these ends ofl warning, guiding, and orienting the navigator.
THE LATERAL SYSTEM
The waters of the U~nited States are marked for safe navigation by
the lateral system of buoyage. This system employs a simple arrange-
ment of colors, shapes, numbers, and light characteristics to show the
side on which a buoy should be passed when proceeding in a given
direction. The characteristics are determined by the position of the
buoy with respect to the navigable channels as the channels are entered
from seaward toward the head of navigation. As all channels do
not lead from seaLward, arbitrary assumptions must at times be made
in order that the system may be consistently applied. The characteris-
ties of buoys are based on the assumption that proceeding in a south-
erly direction along the Atlantic coast, in a northerly and westerly
direction along the Gulf coast, in a northerly direction on the Pacific
coast, and in a westerly and northerly direction on the Great Lakes
(except Lake Michigan) and in a southerly direction in Lake Mlichi-
gan is proceeding from seaward. On the Intracoastal Waterway pro-
ceeding in a general southerly direction along the Atlantic coast, and
in a general westerly direction along the Gulf coast is considered as
proceeding from seaward. On the Mississippi and Ohio Rivers~ and
their tributaries the aids to navigation characteristics are determined
as proceeding from sea towards the head of navigation although local
terminology describes "left bank" and "'right bank" as proceeding
with the flow of the river.






is AIDS TO MARINE NAVIGATION OF THE UNITED STATES



i B AIDS TO NAVIGATION ON NAVIGABLE WATERS
except Western Rivers and Intracoastal Waterway

LATERAL SYSTEM AS SEEN ENTERING FROM SEAWARD


BUOYS HAVING NO LATERAL SIGNIFICANCE--ALL WATERS
NO SPECIAL SHAPES. NO NUMBERS, MAY BE LETERED. WHITE LIGHTS ONLY. FIXED ---- FLASHING -mmam OCCULTING -acli-ar


*C *C C"N" *C C
SPECIAL QUARANTINE ANCHORAGE FISH NET DREDGING
PURPOSE ANCHORAGE

RANGE DAYMARKS






NOTES: A. Ouick flashing Ilghts rmark Important turns. wrecks, etc., where panlcular caution is required. B. RaRef on chart indicates radar reflctor installed.


PORT SIDE
ODD NUMBERED BUOYS OR STRUCTURES
WITH WHITE OR GREEN LIGHTS
FIXED OCCULTING ~ '-
FLASHING sma QUICK FLASHING I~m


MID CHANNEL
NO NUMBERS. MAY BE LETERED
WHITE LIGHTS ONLY
MORSE CODE


STARBOARD SIDE
EVEN NUMBERED BUOYS OR STRUCTURES
WITH WHITE OR RED LIGHTS
FIXED OCCULTING -
FLASHING~ am QUICK FLASHING sm




WHISTLE











NUN eN 6"







DAYMARKS





POINTER


RaRef


LIGHTED


CAN


8Wr


NUN N"L"
PREFERRED CHANNEL
TO PORT
TOPMOST BAND
IS RED


5
BN"B"
NUN


I F
CAN C"7"


JUNCTION
MARKS JUNCTION AND OBSTRUCTIONS.
PASS ON EITHER SIDE. NO NUMBERS.
MAY BE LETTERED. WHITE, RED,
OR GREEN LIGHTS.
INTERRUPTED QUICK FLASHING


DAYMARKS


I RB n
CAN C"N"
PREFERRED CHANNEL
TO STARBOARD
TOPMVOST BAND IS
BLACK


POINTER




AIDS TO MARINE NAVIGATION OF THE UNITED STATES 19

SPECIAL PURPOSE BUOYS
In addition to the Intera~l system of buoyage, several special purpose
buoyage characteristics, which have no lateral significance, are ult ilizedl
to mark dredging+ areas, quarantine areas, fish net areas, anchorages,
race courses, experiments or tests, etc.

TYPE OF BUOYS
The buoyage system adopted for thne waters of the United States
consists of several diAferent types of buoys, each kind designed to serve
under definite conditions. Broadly speaking, all buoys serve as day-
marks, those having lights are also available for navigation by night,
and those having sound signals are also more readily located in time
of fog as well as by night. The following are the principal general
types.
SPAR ]BUOYs.--Large logs, trimmed, shaped, and appropriately
painltedl. Buoys of the same spar shape are also constructed of steel
plates.
CAN AND) NUN BUJOPs.--Buoys built up of steel plates having the
d ist i nct i ve shapes designated by these names.
BELL BU~O~s.--Steel floats surmounted by short skeleton towers in
which the bells are fixed. Most bell buoys are sounded by the motion
of the buoy in the sea. In a few buoys the bells are struck by com-
pressed gas or electrically operated hammers.
Gowa Bnoos.--Similar in construction to bell buoys, but sounding
a distinctive note because of the use of sets of gongs each gong of
which has a different tone.
WHISTLE BoUOs.--These buoys provide a sound signal which is
useful at night and also during fog and low visibility. As the whistle
mechanism is operated by the motion of the buoy in the sea, these
buoys are used principally in exposed locations.
A type of sound buoy is also in use in which a HoRN is sounded at
regular intervals by mechanical means.
LIGHTED BUOYS.--A metal float on whnichn is mounted a short skeleton.
tower at the top of which the lantern is placed. A power source for
the light is placed in the body of the buoy below the water level.
COMBINATION BUOYs.--These are buoys in which a light and a sound
signal are combined, such as a lighted bell buoy, lighted gong buoy,
lighted ~h istle buoy, or lighted horn buoy.
Most modern buoys have corner radar reflectors designed into the
superstructures to improve the radar response.
DAYLIGHT CONTROLS.--Certain lighted buoys are equipped with a
sperin1 device which automatically controls the electric current to the





20 AIDS T`O MARINE NAVIGATION OF THIE UNITED STATES

light. This device causes the light to operate during hours of darkness
and to be extinguished during daylight hours. Lighted buoyrs equip-
ped with, these daylight controls wCill be marked with a white circular
spot 2 inches in diameter, with a white horizontal bar 4 inches long and
3/4 inches wide through the center i.e. -*-.

COLORING OF: BUOYS
All buoys are painted distinctive colors to indicate their purpose or,
in the lateral system, the? side on which they should be passed. The
meaning of lateral system buoys, when, proceeding from seaward (see
Lateral System) as indicated by their colors as followcps:
BLACK BUOIYS mark the port (left) sides of channels, or thne loca-
tion of wrleek~s or obstructions which must be~ passed by keeping
the buoy on the port (left) hand.
RED BUOYS mark the starboard (right) sides of channels, or the
location of wr1ee~ks or obstructions which must be passed by keep-
ing the buoy on the starboard (right) hand.
RED AND BLACK HORIZONTAL BANDED ]BUOYs mark junctions in.
the channel, or wFrecks or obstructions which, may be passed on
either side. I~f thne topmnost band is black, the preferred chan-
nel will be followed bly keeping the buoy on the port (left)
hand. If the topmost band is red, the preferred channel wccill
be followed bly keeping the buoy on the starboard (right) hand.
(NOTE.-When proceeding toward seaward, it may not be pos-
sible to pass on either side of these buoys, and the chart should
always be consulted.)
BLACKI AND WHITE VTERT`ICALLY STRIPED BUOYs mark the fairway
or midchannel and should be passed close to, on either side.
The meaning of special-purpose buoys is indicated by their colors as
follows :
White buoys mark anchorage areas.
Yellow buoys mark quarantine anchorage areas.
WJhite buoys with green tops are used in connection with dredging
and survey operations.
White and black alternate horizontally banded buoys mark fish
net areas.
White and international orange buoys alternately banded, either
horizontally or vertically, are for special purposes to which
neither the latteral-system colors nor the other special-purpose
colors apply.
Yellow and black vertically striped buoys are used for sendrome
markings and have no marine significance.




AIDS TO0 MARINE: NAVIGATIONi OF THCE UNITED STATES 2

NUMBERING OF: BUOYS

Most buoys are givenr nrmber~s, letters, or combllina~tions of numbers
and letters which. are painted conspicuously~ upon themr. These mark-
ings facilitate idenltifientio~n and location of the buoys on thre charts.
All solid-colored red or black buoys, except those in the MIississippi
River aids to naviga~ti~n ~systemn, are given numbers or combinations of
numbers and letters. Other colored buoys mayr be given letters.
NPumnbers i ncrea-se from sea\\;ard and. are kept in approximate sequence
on both sides of a, channelll by omitting numbers there r'equlir~ed. Odd
numbers are used only on solid-blackr buoys. Even numb~l:ers are used
only on solid-red buoys. Numbers followed by letters are used on
solid-colored red or black buoys when a letter is required so as not to
disturb the sequlence of numbering or on important buoys, particularly
those man'lilrkin isolated offshore dangers. An example of the latter
case would be a buoy marked "~1DR" which in this instance the number
has the usual signlifie~nnce, whlile the letters "DR") indicate the place as
D~uxbury Reef. L~etter~s without num-bers are applied in some cases
to black and white vertically striped buoys, red and b~lack; horizontatlly
banded buoys, solid-yellowf buoys, and other buoys not solid colored
red or black.
In the Mississippi River systemrr, unlighted buoys are not numbered,
while the numbers on lighted buoys hazve no lateral significance but
hindicate the number of miles from a designated point.

SHAPES OF BUOYS

In order to provide ready identification, certain unlighted buoys
arpe differentiazted by shape.
RED BUOYS, OR RED AND BLACKC HORIZONTALLY BANDED BUOYS with
the topmost band red are conical shaped and called nun buoys.
BLACKS ]BUOYS, OR RED AND BLACKI HORIZONTALLY BANDED ]BUOYS
with the topmost band black are cylindrical shaped and called canl
buoys.
BLACK: AND HY-ITE VERTICALLY STRIPED nUOYS may be either nun or
canl buoys. The shape has no significance in this case.
Full reliance should not be plaledl on thle shape of an ~unlighted buoy
alone. Charts and light lists should be consulted to ascer~tain the sig-
nificance of unlighlted buoys as determined by their colors.
LIGHTED ncUOYS, Sor.No BUOos, AND SPAR RrUOYS arT nOt clitferenl-
tiated by shanpe to indiclt~e the sider on wc\hich they should be pass~ed.
Since no special significance is attached to the shatpes of these buoys,
their purpose is indienlted by the coloring, numbering, or light
charzc~t erIst ics.





22 AIDS TO MARINE NAVIGATION OF` THE UNITED STATES

COLOR OF LIGHTS

1Red lights on buoys are used only on red buoys or red and black
horizontallly banded buoys with th~e topmost band red. Green lights
on buoys are used only on black buoys or red and black horizontally
handed buoys with the topmost hand black. White lights on buoys
are used on any color buoy. No special significance is attached, to a,
white light on a buoy, the purpose of the buoy being indicated by its
color, number, or its light phase characteristic.
OPTICAL REFLECTORS
Many unlighted buoys are fitted with, optical reflectors. These
greatly facilitate ~the locating of the ;buoys at night by means of a
searchlight,. Optical reflectors may be white, red, or green, and have
the same significance as lights of these colors.
RADAR REFLECTORS
Most modern buoys have corner radar reflectors designed into
the superstructure to improve the radar response.

LIGHT PHASE CHARACTERISTICS
FLASHING LIGourIs (flashing at regular intervals and at the rate of
not more than 30 flashes per minute) are placed only onl black buoys,
red buoys, or special purpose buoys.
QUICK FLASHING LIGHTS (HOt l8Ss than 60 flashes per minute) are
placed only on black; buoys and on red buoys, at points where it is
desired to indicate that speial''r; cewtl~oio is required, as at sharp turns
or sudden constriction~, or where used to mark wrecks or dangerous
obstructions which must be passed only on one side.
INTERRITPTED UInCK FLASHING Llours (t~he groups consisting of a
series of quick flashes, with dark intervals of about 4 seconds between
groups) are placed only onl buoys painted with red and black hori-
zontal bands, at points where it is desired to indicate junctions in
channels, or wrecks or obstructions whi~ch. may be passed on either side.
M1ORSE CO~DE FLASHING LIGHTs (groups consisting of a short flash
and a long flash, providing the letter "A" of thne M/lorse Code, the flashes
recurring at the rate of about eight per minute) are placed only on
buoys paintted in black and white vertical stripes, at points w~ihere it is
desired to indicate fairways or midchannels and should be passed
close to, on either side. The lights are always wPhite.
In order that lighted buoys may function for a reasonably long period of time
without requiring a replenishment of the power supply, the length of the light
flashes as compared with the intervening periods of darkness is made quite
short. Buoys at isolated points frequently function for 6 months or more without
attention.





AIDS TO MARINE NAVIGATION OF THE UNITED STATES 23

DAYBIEACONS

There are many aids to navigation wFhich are not lighted. Strue-
tures (not buoys) of this type are called daybeacons. They vary
greatly in dlesignl and construction,' depending upon their location,
and the distance to which they must be seen. Daybeacons are colored,
as are lighthouses, to distinguish them from their surroundings and
to provide a means of identification. Daybeacons marking the sides
of channels are colored~~ and numbered in the same manner as buoys
and minor light structures; red indicating the right side entering,
and black the left side entering. Many dly~beacronls are also fitted with
op~tica:l reflectors to facilitate locating thleml at night by means of a
searchlight.

INTRACOASTAL WATERWAY

DEFINITION
The Intracoastal Waterwoay, to which is applied the system of mark-
ing about t~o be described, is that comparatively shallow channel lying
parallel to and extending along the Atlantic and Gulf coasts from
Nuew Jersey to the Mexican border. The special marking is applied
to thle so-called "inside route") proper and to those portions of all
connecting waterways which must be crossed or followed in. order to
make a continuous passage.
DISTINCTIVE MARKING
All buoys, daybeacons, and light structures marking the Intra-
constal Wiaterway have some portion. of them painted yellow. This
is the dlistinlctie, coloring adopted for the Waterway. Buoys have
a band of yellow at the top, daybeacons have a band or border of
yellow, and light structures are similarly painted.
T~he coloring and numbering of buoys and dalybeacons, and the
color of the lights on buoys and on light structures is on the same
lateral system as that prevailing in other wraterwrays. The basic rule
is that RED buoys and daybeacons are on the right-hand side of the
channel when proceeding from N'ew Jersey toward M~exico, and
BLA~PCK buoys and daybeacons are on the left-hand side of the chan-
nel when proceeding in thne same direction. TIhis rule is applied in. a
uniform manner from one end of the Intracoastal W~aterwvay to
the other, regardless of the widely differing compass headings of the

1A constant effort is being made to standardize daybeacon markings which have become
established by custom over many years.





24: AIDS TO MARINE NAVIGATION OF THE UNITED STATES

many sections, and the fact that rivers and other waterways marked
on the seacoatst system are sometimes followed.
Nu'lmb~ering of Ilt~ntrcoastall W;aterway aids follows the basic rule,
numbers increacsilgr from New Jersey toward Mexico. Aids are
munbr~ler~ed in groups, ulsually not exeed~ilgr 200; numnbering: begins
again at "'1" at certain natural dividing points.
Lights on buoys followr the standard system of red or white lights
on red buoys, and green or white lights on black buoys. TPh~e color
of the lights on fired structures also follow this general rule. Range
lights, not being lateral ma rklers,, may be any of the three standard
colors.
DUAL MARKING
In order that vessels may readily follow the Intracoastal W~ater-
waLy route where~t it coincides with another watferwMay such as an imn-
portantt river marked on the sen;cons;lt system, special markings are
employed. These special markings are applied to the buoys or other
alids w-hichz mark the river or walterw~ay for other traffic. The special
marks consist of a yellow square and a yellow- triangle, painted on a
conspicuous part of the dual-purpose aid. The yellow square, in out-
line similar to a can buoy, indicates thazt the aid on which. it is placed
should be kept. on1 the left hand when following the Intracoastal
Wiaterwa\;y from New- Jersey toward MIexic~o. The yellow triangle, in
outline similar to a, n~un buoy, indie~ntes that the aid on which it is
placed should be kept on the right hanld when following the Intra-
c~on stal Waterwa'\.;y from Ne w\ Jersey toward ~e xi co. By this marking,
the matriner approaching a body of water such as the Savannah Ri~ver,
aLnd knowing that he must follown it for some distance before again.
entering a dredged cut of the Intral~cons.tall Wat~erway, knows that his
course lies along such buoys or other aids as are specially marked in
yellow. He de~term11ines the side of: his vessel on which these aids
should be passed by the shape of the yellow marks, bearing always in
mind the basic direction of his travel.
Where coincidental marking is emnplolyed, the matriner following
the Intracoazstal Wa~terwa.;y disregards the color and shape of the aid
on which the mark is placed, being guided solely by the shape of the
yellow mark. Can. buoys of the senconst system may have painted
upon them yellow triangles or yellow squares, depending on whether
the wa~terw~ay which, they mark is followed in the directions of the
sea or in the direct ionl of its headwaters, as the Intracoalstal W~ater-
way is followet d in. thle direction of Mesic~o. lMarinlers not traversing
the Intracoastatl Waterway entirely disregard the sp~ecial yellow
m arkings.








































































I I
RANGE: DAYMARKS






III ID 8 11
NOTE: The ICW eaid are characterize by the yellow border m so sa ouren


AIDS TO MARINE NAVIIGATION OF THE UNITED STATES 2;5




Ai~ AIDS TO NAVIGATION ON THE INTRACOASTAL WATERWAY


AS SEEN ENTERING FROM NORTH AND EAST AND PROCEEDING TO SOUTH AND WEST


PORT SIDE
ODD NUMBERED BUOYS OR STRUCTURES
WITH WHITE OR GREEN LIGHTS
FIXED OCCULTING anrial
FLASHING miss QUICK FLASHING m



BELL OR
WHISTLE


LIGHTED BUOY "3"


JUNCTION
MARKS JUNCTION AND OBSTRUCTIONS
PASS ON EITHER SIDE. NO NUMBERS.
MAY BE L E TRD. WIE. RED'

INTERRUPTED QUICK FLASHING






LIGHTED









CAN C"A" NUN N"s"


STARBOARD SIDE
EVEN NUMBERED BUOYS OR STRUCTURES
WITH WHITE OR RED LIGHTS
FIXED OCCULTING a-aw--
FLASHING mla QUICK FLASHING Eml




WHISTLE











NUN N"6.







DAYMARKS "4"


PREFERRED CHANNEL
TO STARBOARD
TOPMOST BAND IS
BLACK


PREFERRED CHANNEL
TO PORT
TOPMOST BAND
IS RED


ILLUSTRATING THE SYSTEM OF DUAL
PURPOSE MARKING WHERE THE ICW
AND OTHER WATERWAYS COINCIDE


BUOY SHAPE AND COLOR BASED ON PRIMARY WATERWAY.
YELLOW SQUARE OR TRIANGLE SHOWS CONSISTENT OR
CONFLICTING USE AS AN ICW AID TO NAVIGATION. ICW
TREATS O AS A CAN AND n AS A NUN REGARDLESS OF
BUOY TYPE OR COLOR.


DAYMARKS -an


POINTER








*C"5"
JOINT






*N"6"


POINTER








*N"6"
JOINT







C"5,,





26 AIDS TO MARINE NAVIGATION OF THIE UNITED STATES


( AIDS TO NAVIGATION ON WESTERN RIVERS

AS SEEN PROCEEDING IN THE DIRECTION OF RIVER FLOW (DESCENDING)


LEFT SIDE
WHITE OR RED LIGHTS
GROUP FLASHING (2)
--------- -


RIGHT SIDE
WHITE OR GREEN LIGHTS
FLASHING


JUNCTION
MARKS JUNCTIONS AND OBSTRUCTIONS.
PASS ON EITHER SIDE.
WHITE, RED OR GREEN LIGHTS.

INTERRUPTED QUICK( FLASHING
--m-mmmu-n-m


LIGHTED BU0Y


LIGHTED BUOY






I
CAN





PASSING DAYMARK


Hf


1
NUN





PASSING DAYMYARK


NUN

PREFERRED CHANNEL
TO THE RIGHT
TOPMOST BAND RED
WHITE OR RED LIGHT


CAN

PREFERRED CHANNEL
TO THE LEFT~
TOPMOST BAND BLACK
WHITE OR GREEN LIGHT


CROSSING DAYMARK


CROSSING DAYMARK


BUOYS HAVING NO LATERAL SIGNIFICANCE--ALL WATERS


NO SPECIAL SHAPES, NO NUMBERS. MAY BE LETTERED. WHITE LIGHTS ONLY. FIXED FLASHING mm m OCCULTING *=~ma


DREDGING


LIG


TED





AIDS TO MARINE NAVIGATION OF THE, UNITED STATES 27

SYMBOLS EMPLOYED UPON CHARTS

In order that mariners may derive the maximum use from, navTiga-
tional aids, they are shown upon the various nautical charts. In this
manner, mariners are apprised of the various aids which they may
expect to pass, and may plot anly bearings which they may take for
the purpose of determining thei r position.
Upon the charts thne aids are! shlowFn by means of a series of con-
vent ionn1 symbols to which are appended various abbreviations giving
condensed information regarding the aids. The principal symbols
and abbreviations are shown on page 18. The meaning of the various
abbreviations are shown on page 6.

LIGHT LISTS

Light Lists describe the aids to marine navigation maintained by
or under the authority of the U~nited States Government, are published
by the Coast Guard. Revised editions appear enclh year. TIhe follow-
ing volumes are issued :
ATLANTIC COAST
LIGH-T LIST, ATLANTIC COAST, VOLUME I, describing aids to naviga-
tion in the United States waters from St. Croix: River, Maine to Little
River, South Carolina.
LloRrr LST, AT`L.\TIC AND rULF COAST, YJOLUME II, describing aids
to navigation in the Ulnited States waters from Little River, South
Carolinaz to Rio Grande River, Tlexas and the Greater Antilles.

PACIFIC COAST
LIGHT LIST, PACIFIC COAST AND PACIFIC ISLANDs, VOLUME III,
describing aids to navigation in U~nited States wa-rter~s on the
Pacific Coast and outlying ]Pacific islands. For the convenience of
mariners there are also included the lighted aids on the Coast of British
Columbia, maintained by the Canadian Government.





28 AIDS TO MARINE NAVIGATION OF THIE UNITED STATES

GREAT LAKES

LtIGHT L;IST, GREAT L;AKES, VOLUME IV, describing aids to navigation
mal~inltainetd by the United States Coast Guard, and the lighted aids
maintained by the D~ominion. of Canada, on the G~reat L~akes and the
St. Lawrence River, above St. Regia River.
MISSISSIPPI RIVER SYSTEM
LIGHT LIsT, MIGsIsisslrt RIVER SYs~rM, VOLU~ME V, describing aids
to navigation on the Mlississippi and Ohio Rivers and navigable tribu-
taries.
Light Lists, are issued to the public on a sales basis. Copies may be
obtained from the Superintendent of Documents, Go~vernment Print-
ing Office, Washington, D.C., or from sales ag~en~ts located in the prin-
cipal ports. A list of sales agents is published semninannually in, the
Weekly Notice to Mariners.

PURPOSE

Light Lists are compiled and published to provide mariners wit
more complete~ details regarding aids to navigation. thnan are to be
found on th~e charts.

NOTICE TO MARINERS
T'he Coast Guard disseminates information concerning establish-
ments, changes, and discontinuances of aids to navigation, in the
United States, its territories, and possessions by means of Notices to
M;arinrers. Reports of channel conditions, obstructions, menaces to
navigation, danger areas, etc., are also included in. Notices to Mariners.
These notices are essential to all navigators for the purpose of keeping
their Light Lists, nautical charts, Coast Pilots, and other nautical
publications currently corrected.
LOCAL NOTICIES TO I1ARIN\ERS are issued by each district commander.
They include changes and deficiencies in aids to navigation within
the area of each Coast Guard district. These notices are published
as required, which. in most districts is daily. If only local informa-
tion is required, the notices issued by the various district commanders
will serve the needs of local navigators. They m~ay be obtained, free
of charge, by making application to the appropriate district
commander.





AID)S TO MARINE NAVIGATIONS OF TIHE UNITED STATES

Section of Page of NOTICE TO MARINERS




;k (2044) IA SSACHU SETTS--Nantucket--Light change~d.--
Nantucket (Great Point) Light has been changed to showv flashing
white every 5 seconds, flash 1 second, with red sector. The intensity
of the white sector has been increased to 25,000 candlepower and the
red sector to 6,000 candlepower. The light has been converted to
automatic operation and resident personnel are no longer in.
attendance.
Approx. position: 41.23'25" N., 70"02'45" WC.
(NJ.M[. 18/59.)
(L.N.M. 27, C.G., Boston, April 3, 1959.)
C. &~ G.S. Charts 250, 1209, 1108, 1107, 71, 70, 1000.
C.G. Light L;ist, Vol. I, 1959, Nos. 62, 401l.
O. & G.S. Coast Pilot, Section B, 1950, page 155.

j~(1838) CALIFORNIA-L-Jos Angeles-LIong Beach Hlarbors--
Lights changed.-1l. Los Angeles Light has been changed to show
flashing green every 15 seconds, flash 0.5 second and the intensity
increased to 300,000 candlepowcer.
Approx. position.: 33"42'30"' N., 118*15'O2"' W.
3. Los Angeles Channel Entrance East Light has been changed to
show flashing white every 10 seconds, flash 1 second.
Approx. position: 38042'39"' N., 118014'37" WC.
(N.M. 16/59. )
(L.N.M[. 17, C.G., Long B~each, March 20, 1959.)
H[.O. Chart 5196.
C. & G.S. Charts 5147, 5148, 5142, 5101, 5002.
C.G. Light List, Vol. III, 1959, Nos. 12, 137, 138.
C. & G.S. Coast Pilot, Pacific Coast, 1951, page 183.

A- (1848) HAWAIIAN ISLAND S-Lanai-KIaumalapau Har-
bor--Buoy established.-1l. Kaumalapau Harbor Lighted Buoy 1,
painted black and showing a flashing green light every 4 seconds,
flash 0.4 second of 30 candlepower, exhibited 10 feet above the water
has been established in 65 feet of water in (approximately)
f20"47'18.6" N., 156*59'42.1" W;.
2. K~aumalapau Breakwater Light previously reported destroyed
has been discontinued.
( Supersedes N.M. 10 (1107) 1959.)
(N.M. 16/59.)
(L.N.M. 15, C.G. Honolulu, March. 18, 1959.)
H.O. Charts 5652, 5655.
C. & G.S. Charts 4122, 4120, 4116, 4130, 4179, 4180, 4102, 4000.
C.G. Light List, Vol. III, 1959, N~os. 2949.1, 2949.
C. & G.S. Coast Pilot, Hawaiian Islan~ds, 1950, page 120.





30 AIDS TO MARINE NAVIGATION OF THE UNITED STATICES

TVEELY,, NOTICE TO MARINERS (PART I-ATL~ANTIC AND 1MEDITER-
RANEAN EDrrION) are prlepar'ed jointly by thne Coast Guard, Treasury
Depaltrtment, and the Oceanographic Office, Navy Department, and
published we~ekly by the UC.S. Naval Oceanographic Office. They in-
clude changes in aids to navigation in assembled form for the 1st, 3d,
5th, 7th, and 8th. Coast Guard D~ist ricts and the Greater AL-ntilles See-
tion. Foreign marine information in the Atlantic and Mediterranean
area is also included in these notices. T1Chese notices are intended for
mariners and others who have a definite need for them in connection
wvith extended seagsoing activities or those op~eratingr in several Coast
G-uard Districts. These notices may be obtained, free of charge, by
making request to the Commander, U.S. Naval Oceanographic Office,
Washington, D>.C., 20390.
TVEEKLY hTO.TIC'ES TO MARINERS ( REAT LAKES EDITION) are8 pub-
lished weekly by the Commander, 9th Coast Guzard District. These
notices may be obtained, free of charge, by making requett to Com-
matnder, 9th Coast Guard D~istrict, Main Post Office Building, Cleve-
land, Ohio, 44113.
WEEKLY NOTICE TO hiARINERS (PART II--PACIFIC AND INDIAN
OCEAN~S EDITIONu) are prepared jointly b~y the Coast Guard, Treasury
D~epartmen~lt, and the Oce~anogralphic Office, Navy D~epartmnent and
published w-eeklyl by the U.S. Naval Oceanographic Office. They in-
clude changes in aids to navigation in assembled form for the 11thn,
12t~h, 13th, 14lth, and 17th Coast Guard Districts. Foreign marine in-
formation. in the Pacific and Indian Oceanls area is also included in
these notices. TIhese notices are intended for mariners and others who
have a definite need for them in connection with extended seagoing
activities or those operating in several Coast Guard Districts. These
notices may ~be obtained, free of charge, by making request to the Com-
mander, UJ.S. Naval Oceanographic Offic=e, WCashington, DI.C., 20390.
MARINE BROADCAST NOTICES TO IkARINERS are made by the Coast
Guard through. Coast Guard, Navy and some commercial radio stations
to report deficiencies and changes in aids to navigation. of importance.
Radio stations broadcasting marine information are listed in "LRadio
Navigational Aids (HO--117A and B) published by the U.S. Naval
Oceanographic Office.
TEMPORARY DEFICIENJCIES in aids to navigation are not published in.
Weekly Not~ices to Mariners when it is known that the defects will be
corrected promptly.
CHABNGE OF ADDRESS.--PerSORS receiVing NOtices to Mariners are!
requested to notify the appropriately agency of any change in address,
or w~hen. Notices to Mariners are~ no longer required. Both new and
old addresses should be driven in case of change of address.
OBTAININa SINGLE COPIESF OF NOTICES TO IMARINERS.--Single copies
of Not ic~es to Ma~~~riners may be obtained or consulted at the offices of





AIDS TO MARINE NAVIGATION OF TH~E UNITED STATES ;j1

the District Commanders, the C=oast and G~eodetic Survely District,
Offices, the Bran~lchl Oceanographic Offices, or other agencies distrib-
uting marine information.

EARLY HISTORY
T1Che maintenance of aids to marine navigation is one of the oldest
Federal functions, the work of erecting and m~aintaining lighlthousess
being provided for at thne first session of Congress by act of August
7, 1789 (the ninth law enacted by Congress). Twelve lighthouses
which had previously been, built by the Colonies were ceded to the
new Federal Government, and became the nucleus of a system of
aids to navigation which over a period of 160 years has been, increased
to a present total of over 40,000.
FEiederal maintenance of aids to navigation was first carried on under
the direct supervision of the Secretary of the TIreasury. Somewhat
later, wrihen the duties of the Secretary of the Tre~asury had greatly
increased, administration, of the aids to navigation was delegated to
thne Commissioner of the Revenue. In 1820, the superintendence of
the lighthouse establishment was assigned to the fifth auditor of the
Treasury, and in 1845 again transferred, this time to the Reveune
Marine Burea~nl an organization which later became the Coast Guard.
The collectors of customs through all this period served as local
superintendents of lighnthouses.
A Lighlthouse Board w~as created in 1852, to administer the con-
stantly expanding service, being composed of officers of the Army
and the Nav~y, and of civilian scientists. In 1903 the Lighthouse
establishment was transferred from the TIreasury D~epartment to the
newly created Department of Commerce and Labor and in 1910, the
Lighthouse Board was superseded by the Bureau of Lighthouses in
the Department of Commerce. On July 1, 1939, the Lighthouse
Service was consolidated with the United States Coast Guard.
The U~nited States Coast Guard today maintains over 40,000 aids
to marine navigation. The greater number of these are lighthouses,
automatic lights, and buoy~s. TIhere are also about 193 radiob~eacons,
25 lightship stations, and about 2,016; fog signals, including those on
buoys.

BRIEF HISTORY OF BUOYAGE

Buoyage of navigiable w3aterways in this country was undertake; n at
least as early as 1767, when, according to available records, buoys were
in use in the D~elaw~are River. The earliest types were simply solid
wooden spars or were built up of staves, similar to a barrel. This





32 AIDS TO MARINE NAViIGAT'ION OF T'HE: UNITED STATES

stave construction was employed in small buoys used near Bostonl
about 1808, but these gave way to spar buoys about 1820, supplemented
by iron buoys in. 1850. A marked improvement was e~ffected in 1900
when tall can and nun buoys were introduced. In 1881, the first
ligh~ted buoy, burning oil gas, was put into service outside Newcp York
Harbor. Electricity was employed from 1888 to 1903 in the Gedney
Channel in. New IYork lower bay. Current for these buoys was
supplied through cables from shore, but this system proved imprac-
tical. Buoys lighted by compressed acetylene gas stored in tanks
within the buoy itself, a type of lighted buoy still in use today,
were introduced in 1910. Bell buoys, in which the bell is struck by
clappers actuated by the rolling of the buoy in the sea, have been
in service! since 1885; and now buoys are also in service in which the
bell is struck at regular intervals by a mechanism operated by com-
pressed gas. WVhistle buoys, the whistle sounded through motion
of the buoy in the sea, have been employed since 1876. Similar buoys
are now available in which a horn is sounded by electrical means.
Tests have also been made of buoys fitted wti~th a ult omnat ic. radiobeacons.
In 1952, due to the increasing importance of radar as an aid to
navigation, all buoy~ designs were changed to incorporate a corner
radar r~efle(tor in the superstructure. Thus all buoys manufactured
since that time have improved radar response.

JURISDICTION

The maintelnance of aids to marine navigation is a function of the
United States Coast Guard, having been placed under that organiz~a-
tion on July 1, 1939, and consists of the maintenance of lighthouses,
lightships, radiobeazcons, 10ran, fog signals, buoys, and daybeacons
upon all navigable.l waters of the United States and its possessions;
including A~tlantic and Pacific coasts of continental UTni~ted States,
the G-reat Lakes, the Mississippi River and its tributaries, Puerto
Rico, the Haw-aiianl Islands, Atlaska, and such~ other plnces where aids
to navigation are required to serve the needs of the armed forces.
TIhe chief administrative officer is th~e Commandant of thLe Coast
Guard, wit~h headquarters at Washington, D.C. The functions of es-
tablishment, construction, maintenance, and operation of aids t~o navi-
gaztion are carried on under his direction. Because of the wide geo-
graphic distr~ib~t ion of aids to navigation on. the sea costs, th-e Great
Lakes and nazvigalble rivers of the United States with an adggregate
coast line of over 40,000 miles, the field wFork of the service is carried on.
by d ist r~ic~t organizations. TPhere are 12 Coast Guard districts, carrying
on ligShthouse w\orkl, as well1 as other functions of the Coast Guard.





AIDS TIO 1MAERINE NIAVIGATIOON OF THE UNITED STATES 33

Ealch dist rict is undler' the supervision of a cormmander, assisted~ by a
suitabflel engineering annd azdministrative force, and. equipped~~ with the
nle~essaryy supply and buoy depots, and with suitable \essels for the
maintenance of the aids to navigation.

RIELATIED NArUTICAL PUBLICATIONS

NOTICE TO MARINERS (see page 27 for details)

Areas within Coast Guard district limits:
Issued by each Coast Guard District Commander.
Firee of c~hargec from. Commander of Coast Guard district concerned.
WlEEKLY NOTICE TO MARINERS (PART I--ATLANTIC AND MEDITERRANEAN EDITION)
are prepared jointly by the Coast Guard, Treasury Department, and the Oceano-
graphic Office, Navy Department, and published w~eekly by the U.S. Naval
Oceanographic Offce. These notices may be obtained, free of charge, by making
request to the Commander, U.S. Naval Oceanographic Office, Washington, D.C.,
20390.
WEEKLY NOTICE TO MARINERS (PART II--PACIFIC AND INDIAN OCEANS EarnowN)
are prepared jointly by the Coast Guard, Treasuryv Department, and the Oceano-
graphic Offtice, Navy Department, and published weekly by the U.S. Naval
Oceanographic Office. These notices may be obtained, free of charge, by making
request to the Commander, U.S. Naval Oceanographic Office, WF~ashington, D.C.
20390.

Great Lakes weekly edition:
Prepared and published by Comlmander, 9th Coast Guard D~istrict, Main Post
Office Building, Cleveland, Ohio 44113.

LIGHT LISTS (see pages 26 and! 27 for details)

Coasts of the United States, Territories, and possessions:

Published by Coast Guard, Treasury Department.
For sale by Superint~endent of Documents, Government Printing Office, Wtash-
ington, D.C., and sales agents.'
Foreign countries:
Published by U.S. Naval Oceanographic Office.
For sale by U.S. Naval Oceanographic Office, Washington1, D.C. 20390, and
sales agents

1A list of sales agents for charts and publications is published semiannually in the
Weekly Notice to Mariners.





34 AIDS TO MARINE N-AVIGATION OF TH-E: UNITJ'ED STATES

RADIOBEACONS AND LORAN (see page 11 for details)

Charts of radiobeacon system, Atlantic and Gulf coasts, Pacific coast, and Great Lakes.
Published by Coast Guard, Treasury Department.

Radio Navigational Aids (H.O. Pub. No. 117A and B):
Published by U.S. Naval Oceanographic Office.
F'or sale by U.S. Naval Oceanographic OfiSce, Washington, D).C. 20390, and
sales agents.l

Loran charts and tables:

Published by U.S. Naval Oceanographic Office.
For sale by Coast and Geodetic Surve~y, Washington, D.C., 20390, and sales
agents.'

NAUTICAL CHARTS

Coasts of the United States, Territories, and possessions:
Issued by Coast and Geodetic Survey, U.S. Department of Commerce.
For sale by Coast and Geodetic Surveyg, Washington., D.O. 20390, and Sales
agents.'

Mississippi River from the Head of Passes to Cairo:
Issued and for sale by the 1Mi~ssissippi Rtiver Commission, Vick~sburg, Miss.

Illinois Waterway System:
Issued and for sale by the U.S. Army Engineer District, Chicago, Ill.

Ohio River:

Issued and for sale by the U.S. Army Engineer District, Ohio River, Gincin-
nati, Ohio.

Great Lakes, Lake Champklin, New York State Canals, and the St. Lawrence River, St. Regis
to Cornwall, Canada:

Issued and for sale by the U.S. Army Engineer District, Lake Survey, De-
troit, Mich.

New York State Canal System:
Issued and for sale by the Superintendent of Public Works, State of New
York, Albany, N.Y.

Foreign countries:
Issued by U.S. Naval Oceanographic Ofic~e.
For sale by U.S. Naval Oceanographic Office, Washington, D.C. 20390, and
sales agents.'

'8A list of sales agents for charts and publications is published semiannually in the
Weekly Notice to Mariners.





AIDS TO 1MARINTE NAVIGATION OF THE UNITED STATES 35

COAST PILOTS

Coasts of the United States, Territories and possessions:
Published by Coast and Geodetic Survey, U.S. Department of Commerce.
For sale by Coast and Geodetic Survey, Washington, D.C. 20230, and sales
agentss'
Foreign countries:
Published by U.S. Naval Oceanographic O~ffice, Navy Department.
For sale by U.S. Naval Oceanographic Offce, W~ashington, D.C., 20390, and sales
agents.'

TIDE TABLES

Atlantic Ocean, and Pacific alnd Indian Oceans:
Published by ,Coast and Geodetic Survey, U.S. Department of Commerce.
For sale by Coast anad Geodetic Survey, WFashington, D.C. 20230, and sales
agenlts.1

CURRENT TABLES

Atlantic Coast, North America, and Pacific Coast, North America, and Philippine Islands:
Published by Coast and Geodetic Survey, U.S. Department of Commerce.
For sale by Coast and Geodetic Survey, ~Washington, D.C. 20230, and sales
agents.'

xA list of sales agents for charts and publications is published semiannually in the
Weekly Notice to Mariners.


SU.S. GOERNMENT PRINTING OFFICE:1965 0--760--711































































































































































































































































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