ABEAMBearing 90° or 270° relative from own
ACPAllied Communications Publication.
CELESTIAL NAVIGATIONNavigation with the
aid of celestial bodies.
official information requires, in the interest of
national security, a specific degree of protection
against unauthorized disclosure, coupled with a
designation signifying that such a determination
has been made.
CODRESS Message having the address buried in
the encrypted text.
COMMISSION PENNANTA long, narrow,
starred and striped pennant flown aboard a
CONVOYA number of merchant ships or naval
auxiliaries, or both, usually escorted by warships
and/or aircraft, or a single merchant ship or naval
auxiliary under surface escort, assembled and
organized for the purpose of passage together.
International and Inland Rules of the Road to
visually indicate particular operations or
situations from one vessel to another.
DEBARKATION STATIONThe place on a ship
where personnel assemble to debark in boats.
DECLASSIFICATION The determination that in
the interest of national security, some classified
material no longer requires any degree of
protection against unauthorized disclosure,
coupled with removal or cancellation of the
DEFENSE MAPPING AGENCYGovernment
agency that produces and sells navigational charts
ENCODETo convert plain text into unintelligible
language, usually word by word, by means of a
FATHOMA unit of length equal to 6 feet.
transmitting signals with predetermined meanings
taken from authorized publications. The U.S. and
Allied Navies use 68 different flags/pennants or
combinations thereof for this purpose.
International use consists of 40 different flags and
FLASHING LIGHTThe term applied to the
transmission of signals by light. The equipment
employed may be directional or nondirectional in
operation. The use of directional flashing light
reduces the possibility of its interseption, thus
providing some security. When security is
required at night, only highly directional flashing
light should be used and its brilliancy should be
the minimum necessary to provide communica-
tion. Nondirectional flashing light permits
simultaneous transmission to a number of stations
in any direction but has little security from
interception, particularly at night.
FORETRUCK The highest point of the forward
FORMATIONAny ordered arrangement of two or
more ships or aircraft proceeding together.
FUSELAGEThe body of an airplane.
GAFFA small spar abaft the mainmast from which
the national ensign is flown when the ship is
GIVE-WAY VESSELAs directed by Rules of the
Road, any vessel required to keep out of the way
of another vessel.
GNOMONIC PROJECTIONA map projection in
which points on the surface of a sphere or
spheroid, such as Earth, are conceived as projected
by radials from the center to a tangent plane.
GREENWICH MEAN TIMELocal mean time at
the Greenwich meridian; the arc of the celestial
equator, or the angle at the celestial pole, between
the lower branch of the Greenwich celestial
meridian and the hour circle of the mean sun,
measured westward from the lower branch of the
Greenwich celestial meridian through 24 hours;