Nautical Abbreviations and Acronyms
As found in Chapman Piloting 62nd Edition by Elbert S. Maloney
Rewritten for the web by Matt Ursin.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Back to TopABYC - American Boat and Yacht Council
AC - Alternating Current
ADF - Automatic Direction Finder, an advanced variation of a radio direction finder, RDF
AM - Amplitude Modulation, one form of radio transmission, modulating the carrier wave in accordance with the strength of of the audio signal.
AP - Advanced Piloting, a course and a grade in the U.S. Power Squadron.
ATON - Coast Guard acronym for Aids to Navigation
B
Back to TopC
Back to TopC - Course, used in marking charts while plotting; Celsius, the metric
temperature scale
CE - Center of Effort
CB - Citizens' Band, a short wave radio frequency service; compass bearing.
CME - Courtesy Motorboat Examination.
CMG - Course Made Good
CNG - Compressed Natural Gas, a fuel used for cooking and heating
CO - Carbon monoxide, a poisonous gas
CO2 - Carbon dioxide; a type of fire extinguishing agent.
COLREGS - U.S. Coast Guard acronym for International Regulations for the Prevention of Collisions at Sea.
CPS - Canadian Power and Sail Squadrons.
CQR - A brand of plow anchor.
D
Back to TopD - Direction, used in labeling data on a chart plot; also distance used in labeling data on a chart plot.
DC - Direct Current
DF - Direction Finder; Direction Finding.
DMA - Defense Mapping Agency
DMAHTC - DMA Hydrographic/Topographic Agency
DR
- Dead Reckoning; label for a DR position on a chart plot.
E
Back to TopE - East, Cardinal compass point.
EP - Estimated Position.
EPIRB - Emergency Position Indication Radiobeacon.
ETA - Estimated Time of Arrival
ETD - Estimated
Time of Departure
F
Back to TopF - Fahrenheit, usually shown as ºF
FBSA - Federal Boat Safety Act (U.S.).
FCC - Federal Communications Commission
FM - Frequency Modulation, a communications technology that changes the frequency of the transmitting radio in accordance with the sound.
FRP - Fiberglass Reinforced Plastics.
G
Back to TopGMT - Greenwich Mean Time; essentially the same as Universal Time Coordinated (UTC).
GPO - Government Printing Office, a source of charts and documents (U.S.).
H
Back to TopH - Hertz, a unit of frequency measurement, equivalent to cycles per second.
HIN - Hull Identification Number.
hp - Horsepower, a unit of power, equal to 746 watts in the U.S.
I
Back to TopICW - Intracoastal Waterway.
IntRR -
International Rules of the Road
J
Back to TopJN - Junior
Navigator, a course and grade in the U.S. Power Squadrons.
K
Back to TopkHz - Kilohertz, unit of radio frequency, one thousand Hertz.
km - Kilometer, one thousand meters, .62 of a statute mile, .54 nautical mile.
kn - Knot, speed measurement, one nautical mile per hour (sometimes "kt").
L
Back to Toplat. - Latitude.
LF - Low Frequency (Loran C)
LNM - Local Notice to Mariners.
LOA - Length Overall
long. - Longitude.
LOP - Line of Position.
Loran-C - Long Range Navigation System using several timed signals from different locations.
LPG - Liquefied Petroleum Gas, a fuel.
M
Back to TopM - Meter, unit of linear measurement.
MF - Medium Frequency
MHW - Mean High Water, a tidal datum for heights.
MHz - Megahertz, unit of radio frequency, one thousand kHz, or one million Hertz.
MLLW - Mean lower low water, a tidal datum for depths.
MLW - Mean low water, a tidal datum for depths.
MSD - Marine
Sanitation Device.
N
Back to TopN - North, cardinal compass point; also Navigator, a course and highest educational grade in the U.S. Power Squadrons.
NavLights - Navigation lights.
NE - Northeast, intercardinal compass point.
NFPA - National Fire Protection Association.
NM - Notice to Mariners
NMMA - National Marine Manufacturers Association.
NOAA - National Oceanic and Atmospheric Administration.
NOS - National Ocean Service, a unit of NOAA.
NW - Northwest, intercardinal point on the compass.
NWS - National Weather Service, a unit of NOAA.
O
Back to TopP
Back to TopP - Piloting, a course and grade in the U.S. Power Squadrons.
PFD - Personal Floatation Device.
PPI - Plan Position Indicator, a type of radar display.
Q
Back to TopQ flag - Yellow quarantintine flag, so-called; the international signal code is "my vessel is healthy and I request free practique."
R
Back to TopRacon - A radar beacon which, when triggered by pulses from a vessels radar, transmits a reply.
RDF - Radio Direction Finder.
rpm - Revolutions
per minute.
S
Back to TopS - South, cardinal compass point; Seamanship, a course and grade in the U.S. Power Squadrons.
SAR - Search and Rescue, Coast Guard and CG Auxilary term.
SE - Southeast, intercardinal compass point.
SHF - Super High Frequency (radar)
SOLAS - Safety of Life at Sea Convention.
SOS - Morse code signal for distress.
SSB - Single Side Band, radio term for a shortwave communications technique.
SW - Southwest, intercardinal compass point.
T
Back to TopT flag - Transportation flag, signal flag hoisted as a signal requesting a tender or launch service.
U
Back to TopUHF - Ultra High Frequency (radio)
UL - Underwriters Laboratories, a safety organization that conducts product tests.
USCG - United States Coast Guard
USCG Aux - United States Coast Guard Auxiliary.
USN - United States Navy.
USPS - United States Power Squadrons.
USWMS - Uniform State Waterway Marking System.
UTC Universal Coordinate Time.
V
Back to TopVHF - Very High Frequency (radio).
VLF - Very Low Frequency (Omega).
W
Back to TopW - West, cardinal compass direction.
WWV - Continuous broadcast time signal station, based in Colorado.
WWVH - Hawaii-based 24-hour radio time signal station.
X
Back to TopY
Back to TopZ
Back to Top