Glossary
15.7
Log: (1) a device used to measure the distance
traveled through the water. The distance
read from a log can be affected by cur-
rents, leeway and other factors, so those
distances are sometimes corrected to a
distance made good.
Longi-
tude:
Imaginary lines drawn through the north
and south poles on the globe used to mea-
sure distance east and west. Greenwich
England is designated as 0° with other
distances being measured in degrees
east and west of Greenwich.
Luff: The forward edge of a sail. To luff up is to
turn a boat’s head right into the wind.
Luff
groove:
A groove in a wooden or metal spar into
which the luff of a headsail is fed.
Lurch: The sudden roll of a boat.
Magnetic
north:
The direction to which a compass points.
Magnetic north differs from true north
because the magnetic fields of the planet
are not exactly in line with the north
and south poles. Observed differences
between magnetic and true north is known
as magnetic variation.
Make
fast:
To attach a line to something so that it will
not move.
Make
way:
Moving through the water.
Marlin
spike:
A pointed steel or wooden spike used to
open up the strands of rope or wire then
splicing.
Mast
Step:
The socket in which the base of the mast
is located.
Measured
mile:
A distance of one nautical mile measured
between buoys or transits/ranges ashore,
and marked on the chart.
Member: A part of the skeleton of the hull, such as
a stringer laminated into fiberglass hull to
strengthen it.
Meridian: An imaginary line encircling the Earth that
passes through the poles and cuts at right
angles through the Equator. All lines of
longitude are meridians.
Messen-
ger:
A small line used to pull a heavier line
or cable. The messenger line is usually
easier to throw, lead through holes or oth-
erwise manipulate than the line that it will
be used to pull.
Midships: A place on a boat where its beam is the
widest.
Mizzen: 1, the shorter, after-mast on a ketch or
yawl; 2, the fore and aft sail set on this
mast.
Moor: To attach a boat to a mooring, dock, post,
anchor, etc.
Mooring: A place where a boat can be moored.
Usually a buoy marks the location of a
firmly set anchor.
Mooring
line:
A line used to secure a boat to an anchor,
dock, or mooring.
Nautical
mile:
Distance at sea is measured in nautical
miles, which are about 6067.12 feet, 1.15
statute miles or exactly 1852 meters.
Nautical miles have the unique prop
-
erty that a minute of latitude is equal to
one nautical mile (there is a slight error
because the earth is not perfectly round.)
Measurement of speed is done in knots
where one knot equals one nautical mile
per hour. A statute mile is used to measure
distances on land in the United states and
is 5280 feet.
Navel
pipe:
A metal pipe in the foredeck through
which the anchor chain passes to the
locker below.
Navi-
gation
lights:
Lights on a boat help others determine
its course, position and what it is doing.
Boats underway should have a red light
visible from its port bow, a green light on
the starboard bow and a white light at its
stern. Other lights are required for vessels
under power, fishing, towing, etc.
Noon
Sight:
A vessel’s latitude can be found, using
a sextant, when a heavenly body on the
observer’s meridian is at its greatest alti
-
tude. The sight of the sun at noon is the
one most frequently taken.
Off the
wind:
With the sheets slacked off, not close-
hauled.
On the
wind:
Close-hauled.
Out haul: A rope used to pull out the foot of a sail.
Outboard: On the side of the hull that the water is
on. Outboard engines are sometimes just
called outboards.
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