APPENDIX I
GLOSSARY
ABEAM—Bearing 90° or 270° relative from own
ship.
ACP—Allied Communications Publication.
CELESTIAL NAVIGATION—Navigation with the
aid of celestial bodies.
CLASSIFICATION —The
determination
that
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 PENNANT—A long, narrow,
starred and striped pennant flown aboard a
commissioned ship.
CONVOY—A 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.
DAYSHAPES —Shapes
specified
in
both
International and Inland Rules of the Road to
visually indicate particular operations or
situations from one vessel to another.
DEBARKATION STATION—The 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
classification designation.
DEFENSE MAPPING AGENCY—Government
agency that produces and sells navigational charts
and publications.
ENCODE—To convert plain text into unintelligible
language, usually word by word, by means of a
code book
FATHOM—A unit of length equal to 6 feet.
FLAGHOIST—A
nondirectional
means
of
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
pennants.
FLASHING LIGHT—The 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
mast.
FORMATION—Any ordered arrangement of two or
more ships or aircraft proceeding together.
FUSELAGE—The body of an airplane.
GAFF—A small spar abaft the mainmast from which
the national ensign is flown when the ship is
underway.
GIVE-WAY VESSEL—As directed by Rules of the
Road, any vessel required to keep out of the way
of another vessel.
GNOMONIC PROJECTION—A 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 TIME—Local 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;
AI-1
