Appendix I, Continued
HALFMAST.To fly a flag halfway up
the mast as a sign of mourning.
HAUL DOWN.A term used as directive
to execute a flaghoist by lowering it.
HONORS AND CEREMONIES.A
collective term; official guards, bands,
salutes, and other activities that honor the
colors, celebrate a holiday, or greet a
distinguished guest or officer.
HUMIDITY.The amount of water vapor
in the air.
HYPERBOLA.A curve that is the locus
of points having a constant difference of
distance from two fixed points.
SYSTEM.A method of radio navigation
(for example, loran) in which pulses
transmitted by two ground stations are
received by an aircraft or ship.
INDEX CORRECTION.That correction
due to index error.
INDICATOR.A device or apparatus,
usually partly or wholly automatic, for
INERTIAL NAVIGATION SYSTEM
(INS).System designed to guide a ship
by a device independent of outside
information, using the inertial properties of
INLAND RULES.Rules of the nautical
road that are applicable in most inland U.S.
INTERNATIONAL RULES.Rules of the
nautical road made effective by agreement
of the major maritime powers for use on
high seas and most inland waters of the
world except the United States.
INTERPOLATION.The process of
finding a value between two known values
on a chart or graph.
IONOSPHERE.That part of Earths
atmosphere between the chemopause (at a
height of about 50 miles) and the
ionopause (at about 250 miles).
ISOBARS.Lines connecting points
having the same atmospheric pressure
reduced to a common datum, usually sea
JOOD.Junior officer of the deck. The
assistant to the officer of the deck.
KNOT.The unit of speed that is
equivalent to 1 nautical mile (6,080 feet
per hour); a collective term for hitches and
LATITUDE.Distance north (N) or south
(S) of the equator, expressed in degrees
sequence and length of light and dark
periods and the color or colors by which it
LIGHTHOUSE.A distinctive structure
exhibiting a major light designed to serve
as an aid to navigation.