Greenwich hour angle of the mean sun, expressed
in time units plus 12 hours.
GUIDE—Vessel designated in a formation or disposition
as the one for others to keep station on.
GUN SALUTE—Blank shots fired to honor a
dignitary or in celebration.
H-HOUR —The term used to designate the time for
an operation to commence.
HEAD-ON VESSEL—One vessel meeting another
on a reciprocal or nearly reciprocal course
involving risk of collision.
HOIST—To move an article vertically upward by
means of some hoisting rig.
HULL DOWN—Said of a vessel when, because of
distance and curvature of Earth, only the
superstructure is visible.
INFRARED —Transmission of signals by light
outside the visual spectrum. This method, which
may be directional or nondirectional, necessitates
the use of special equipment and affords greater
security than normal visual means.
IRISH PENNANT—A loose end of line carelessly
left dangling.
JANAP—Joint Army-Navy-Air Force Publication.
LATITUDE—Distance north (N) or south (S) of the
equator, expressed in degrees and minutes.
LONGITUDE—Distance east (E) and west (W) of the
prime meridian, which runs through Greenwich,
England.
LORAN—An electrical navigation system by which
hyperbolic lines of position are determined by
measuring the differences in the time of reception
of synchronized pulse signals from two fixed
transmitters.
MANEUVERING BOARD—A polar coordinated
plotting sheet devised to aid in the solution of
problems involving relative movement.
MASTHEAD LIGHT—The white running light
placed over a vessel's fore-and-aft centerline
showing an unbroken light over an arc of the
horizon of 225°, fixed to show the light from right
ahead to 22.5° abaft the beam on either side of the
vessel.
MEAN TIME—Time based upon the rotation of
Earth relative to the mean sun.
MERCATOR PROJECTION —A conformal
cylindrical map projection in which the surface of
a sphere or spheroid, such as Earth, is conceived
on a cylinder tangent along the equator.
MESSENGER—(l) A line used to haul another
heavier line across an intervening space; (2) One
who delivers messages.
NEED-TO-KNOW —A criterion used in security
procedures that requires the custodians of
classified information to establish, prior to
disclosure, that the intended recipient must have
access to the information to perform his/her
official duties.
NIGHT VISION DEVICES—Precision instruments
that use electronic optics for observation,
surveillance, and navigation. Also referred to as
Night-Vision Sights.
NTP—Naval Tactical Publication.
NWP—Naval Warfare Publication.
OCCULTING LIGHTS—A navigational aid in
which the period of light is equal to or more than
the period of darkness.
OCCUPATIONAL STANDARDS—The minimum
requirements for enlisted occupational skills of a
certain rate or rating.
OFFICIAL INFORMATION—Information that is
owned by, produced by, or subject to the control
of the United States Government.
OFFICIAL VISIT—A formal visit of courtesy
requiring special honors and ceremonies.
OMEGA —An electronic navigational system.
PELORUS—Device for taking relative bearings.
PERSONNEL QUALIFICATION STANDARDS—
Qualification for officers and enlisted personnel
to perform certain duties.
PHYSICAL SECURITY—That part of security
concerned with physical measures designed to
safeguard personnel; to prevent unauthorized
access to equipment, installations, material and
documents; and to safeguard them against
espionage, sabotage, damage, and theft.
POSITION ANGLE—The number of degrees an
object seen in the sky is above the horizon.
POWER-DRIVEN VESSEL—Any vessel propelled
by machinery.
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