Glossary
15.3
Center
of effort
(COE):
The point at which all the forces acting on
the sails are concentrated.
Center
of lat-
eral resis-
tance
(CLR):
The underwater center of pressure about
which a boat pivots when changing
course.
Center-
board:
A board lowered through a slot in the keel
to reduce leeway.
Chain
pawl:
A short lug which drops into a toothed
rack to prevent the anchor chain running
back.
Chain
plate:
A metal plate bolted to the boat to which
the shrouds or backstays are attached.
Channel: A navigable route on a waterway, usually
marked by buoys. Channels are similar
to roads where the water is known to be
deep enough for ships or boats to sail
without running aground.
Chart
datum:
Reference level on a chart below which
the tide is unlikely to fall. Soundings are
given below chart datum. The datum level
varies according to country and area.
Chart
table:
A table designated as the area in the boat
where the navigator will study charts and
plot courses.
Chine: The location where the deck joins the hull
of the boat.
Chop: Small, steep disorderly waves.
Cleat: A wooden, metal or plastic fitting around
which rope is secured.
Clevis
pin:
A locking pin through which a split ring is
passed to prevent accidental withdraw.
Clew: The after, lower center of a sail where the
foot and leech meet.
Close
reach:
The point of sailing between close-hauled
and a beam reach, when the wind blows
forward of the beam.
Close-
hauled:
The point of sailing closest to the wind;
see also beat.
Close-
winded:
Describes a boat able to sail very close
to the wind.
Coaming: The raised structure surrounding a hatch,
cockpit, etc., which prevents water enter
-
ing.
Compass
course:
The course as read on a compass. The
compass course has added the magnetic
deviation and the magnetic variation to
the true course.
Compass
rose:
A circle on a chart indicating the direction
of geographic north and sometimes also
magnetic north. Charts usually have more
that one compass rose. In that case the
compass rose nearest to the object being
plotted should be used as the geographic
directions and magnetic variations may
change slightly in different places on the
chart.
Coordi-
nated
Univer-
sal Time
(UTC):
The international time standard. It is the
current term for what was commonly
referred to as Greenwich Meridian Time
(GMT). Zero (0) hours UTC is midnight
in Greenwich England, which lies on the
zero longitudinal meridian. Universal time
is based on a 24 hour clock, therefore,
afternoon hours such as 4 p.m. UTC are
expressed as 16:00 UTC (sixteen hours,
zero minutes). Since a day is 24 hours
long, the world may be split into 15 degree
wide longitudinal bands (360 degrees/24
hours). Each band represents one hour.
As an example, Huntsville Alabama is
located at approximately 90 degrees west
longitude, hence, local time lags UTC
time by 6 hours (90/15, assuming Central
Standard Time, 5 hours in Central Daylight
Time). So, if the universal time is 14:30
UTC, United States Central Standard
Time would be 8:30 am CST. <http://www.
ghcc.msfc.nasa.gov/utc.html>
Cotter
pin:
Soft, metal pin folded back on itself to
form an eye.
Course: The direction in which a vessel is steered,
usually given in degrees; true, magnetic
or compass.
Cringle: 1, a rope loop, found at either end of a line
of reef points; 2, an eye in a sail.
Current: The movement of water, due to tides, river
movement and circular currents caused
by the motion of the earth.
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