GLOSSARY
Of
SAILING TERMS
Aback - With
the wind on the wrong side of the sails.
Abaft -
Behind an object in relation to the bow.
Abeam - At
approximately right angles to the fore-and-aft line of the boat.
Advantageous
Side - The side of the rhumb line that provides a faster course to
the mark.
Advantageous
Tack (or Gybe) - That tack or gybe which provides a faster course to
the mark.
Aft -
Toward the stern.
Alee -
Downwind, toward the leeward side.
Amidships - The
center of the boat.
Angle
of Incidence - The angle of the horizontal chord of a sail to the airflow
(or an underwater fin to the water flow).
Apparent
Wind - The wind that impinges upon the sail, a combination of the
true wind and the boat wind.
Appendages - The
fin and rudder and any wings attached thereto as well as any other attachments.
Approach
Tack - The tack that is headed toward and will terminate at the
starting line, the mark, the lay line, or the like.
Aspect
Ratio - The ratio between the height and width of a rig, or depth and
width of a hull appendage.
Astern -
Abaft the boat.
Attached
Flow - That portion of the airflow, which bends to follow the
contour of the leeward surface of a sail.
Baby
Stays - The shortest of the side stays used to control mast bend in
the lower half of the mast.
Back - A
counterclockwise shift in wind direction.
Backstay - An
adjustable line that supports the mast.
It runs from the transom of the hull to the mast crane.
Backwind - The
turbulent airflow in the wake of a sail.
Balance
- A stable state, resulting from the production of aerodynamic and
hydrodynamic forces of equal strength and opposite alignment, which permits a
boat to sail course at the optimal rudder angle.
Balanced
Rudder - One that carries 10% or so of its area forward of its pivot
point.
Base
Leg - The course taken by a boat prior to, and in preparation for,
the assumption of the approach to the starting line.
Batten - Thin
strips of wood, plastic, or other material attached to the leech of the sail.
They impart needed stiffness and flatten the latter portion of the sail.
Beam - The
maximum width of the boat.
Beam
Reach - A point of sailing at which the wind is directly abeam.
Bear
Away, to - To turn a boat away from the wind.
Beat - The
course to the windward mark at a close-hauled sailing angle.
Beneath - To
leeward of.
Blanket - The
reduction and disturbance in the airflow to leeward of the sail.
Boat
Speed - The ability of a boat to sail rapidly.
Boat
Wind - The wind created by the forward movement of a boat.
Boom - A
long pole used to extend the bottom of a sail.
Buoy - See
Mark
Bow - The
front of the boat. (Also, Stem)
Bowsie - A
fitting used to control the length of a line.
Broach - An
abrupt yaw associated with marked heeling consequent to a sudden disequilibria
between aerodynamic and hydrodynamic forces.
Broad
Reach - A point of sailing at which the wind is slightly aft of
abeam.
Bulb - The
ballast attached to the bottom of the fin.
Camber - The
curve of a boats sail, both vertical and horizontal.
Center
of Gravity (CG) – The point at which all of the weight of
an object can be considered to be concentrated.
Chain
Plates - Deck fittings to which the side shrouds are attached.
Chord - A
straight line joining the ends of an arc of a circle or curve.
Clear
Air - Airflow undisturbed by the presence of other boats.
Clear
Ahead - A boat is clear ahead
when her hull and equipment are ahead of a line abeam from the aftermost
point of that boat's hull and equipment.
Clear
Astern - A boat is clear astern when her hull and equipment are behind
a line abeam from the aftermost point of the other boat's hull and equipment.
Cleat - A
fitting used to secure a line under strain.
Clew - The
bottom corner of a sail at its trailing edge.
Clew
Outhaul - An adjustable line running from the clew to the end of the
boom. It is used to slacken or tighten the foot of the sail.
Close-hauled - A
boat sailing as close to the wind as possible is said to be close-hauled.
Close-hauled
Course - Course sailed by a boat attempting to make maximum progress
to windward.
Close
Reach - A point of sailing at which the wind is slightly forward of
abeam.
Come
About - To change tacks.
Course - See
Heading
Cover,
to - To maintain a position of advantage with respect to a
competitor.
Cross - To
pass in front of another boat.
Cross
or Tack? - A hail from a right-of-way boat giving an approaching
give-way boat the option of crossing or tacking away.
Cunningham - See
Downhaul
Dead
Ahead - The position of a boat directly ahead of another and on the
same course.
Dead
Air - See Hole
Dead
Downwind - Directly to leeward.
Dead to
Windward - Directly to windward.
Dip - See
Duck
Dirty
or Disturbed Air - The deviated, eddying, airflow astern
and to leeward of a competitor.
Disadvantageous
Tack (or Gybe) - That tack (or gybe) which provides a longer, or
slower, course to the mark.
Displacement – The
amount of water a boat displaces; the weight of the boat.
Down - See
Low (2).
Downhaul - A
line at the tack of a sail, used to control luff tension.
Downwind - To
leeward; in the direction toward which the wind is flowing; opposite to the
wind direction.
Downwind
End - The end of the starting or finish line farther to leeward.
DNF - An
acronym for Did Not Finish.
DNS - An
acronym for Did Not Start.
Draft - (1) The depth (degree of concavity) of the cross
section of a sail.
(2) The depth of water required
to float a boat.
Drag -
Resistance caused by a body moving through water or air.
Duck - To
alter course to pass behind another boat.
Ease - To
adjust running rigging by loosening.
Entry
Angle – The angle between the chord line and a line tangent to the
luff of a sail.
Fair - A
smooth curve with no bumps or depressions.
A hull is said to be fair.
False
Tack - A tack that is begun only to be abandoned, in an attempt to
trick a competitor.
Fairlead - (1) The exit point through the hull for the
main or jib sheet.
(2) A
fitting used to control the direction of a line.
Favored
End - The upwind end of the starting line.
Fin - A
narrow vertical appendage that extends below the waterline. Acts as a vertical stabilizer, minimizing
side-wise motion or leeway when the boat is underway.
Fittings -
Equipment used to control lines.
Fluke - An
unpredictable change in wind direction.
Flyer -
Course opposite to that taken by the vast majority of the fleet.
Foot - The
bottom edge of a sail.
Foot,
to - To sail rapidly by bearing away slightly below the
close-hauled course.
Fore
and Aft - Along the line of the keel.
Forestay - An
adjustable line running from the bow or bowsprit to the top of the mast
(masthead). Seldom used on non-scale model racing yachts.
Fractional
Rig - A rig where the jib stay is connected to the mast at
approximately 80 percent of the mast height.
Freeboard - The
distance from the water to the deck edge.
Freedom to Tack - The ability of
a boat to tack without interfering with a competitor.
Full
Rig - The modern term describes a rig where the jib stay is
connected to the masthead.
Gate – A pair
of marks, which the sailing instructions require to be passed between or on a
specified side.
Give
Way Boat - A boat not having the right-of-way, which must not interfere
with a right-of-way boat sailing her desired course.
Gooseneck - A
flexible hinged fitting which securely retains the main boom to the mast.
Gust - A
sudden, brief increase in wind velocity, usually the consequences of a
downdraft from the upper airflow.
Gybe - To
change direction while sailing downwind so as to cause the main boom to shift
to the other side. (Also, Jibe)
Gybe
Mark - The mark that terminates the first reach and requires a gybe
to round.
Halyard - A
line used to raise and lower a sail.
Hard
Over - To put the helm over in either direction as far as possible.
Harden
Up - To trim sails in order to sail closer to the wind.
Head - The
top corner of a sail.
Heading - The
direction in which a boat is sailing.
Headboard - A
reinforcing fitting attached to the head of a sail.
Headed
Gybe - The gybe that is affected by a header, which may permit a
boat to assume a direction more in line with the median wind while keeping the
same sailing angle.
Headed
Tack - The tack that is affected by a header, which forces a boat to
point away from the median wind.
Header
or Heading Shift - A shift in wind direction toward the
direction in which the boat is sailing.
Heave
to - To bring the boat's bow into the wind so as she will stay
there.
Heavy
Air - Airflow with a velocity exceeding (for small models) 9 knots.
Heel - The
inclination of the boat while underway.
Helm - (1)
The area of the stern where the boat is steered.
(2) The
combination of forces on the rudder that causes the boat to round into the wind
or away from the wind. Windward helm
rounds the boat into the wind, leeward helm away from the wind.
High - To
windward or farther to windward. (Also,
UP)
Higher,
to sail - To sail closer to the wind.
Hole - A
brief, localized reduction in wind velocity.
Hounds – The
point on the mast where the jib stay is attached.
Hydrodynamic
Force - The force, produced by the movement through the water of a
hull and its fin, which opposes the aerodynamic force.
Inside -
Between a competitor and the mark, or the rhumb line.
Interference - The
consequences of the intervention of a competitor between a boat and the wind.
Jack
Line - A line, usually wire, attached to the mast and used to bend
the mainsail to the mast via hooks or slides.
Jib - A
triangular sail whose luff is attached to the jib stay.
Jib
Club - A shorter jib boom, which is attached to the deck at a point
slightly aft of the deck fitting for attachment of the jib stay. In this case
the jib tack is not attached to the boom.
Jib
Rack - A model yacht deck fitting to which the jib boom is attached.
Jib
Stay - An adjustable line running from the deck or the fore end of
the jib boom to another high up on the mast or to the masthead.
Jibe - To
change direction while sailing downwind so as to cause the main boom to shift
to the other side. (Also, Gybe)
Jumper
Stays - Short stays used to control mast bend above the spreaders.
Jumper
Strut - A spreader whose arms form an approximate 90 degree angle and
face forward. Used with the jumper stays.
Keel - The
backbone of a boat.
Kicking
Strap - An adjustable line or fitting used to control the vertical
angle of a boom. (Also, Vang)
Lay, to - To
assume a course that permits passing the mark on the proper side.
Lay
Line - The course that permits a close-hauled boat or a boat at an
optimal sailing angle on the run to just clear the mark in the existing wind.
The "new lay line" is the lay line after a wind shift.
Leech - The
aft edge of a sail.
Leech
Line - See Topping Lift
Lee-Bow
Effect - The adverse effect of the backwind of a leeward boat upon the
performance of a windward boat; a boat in the lee bow position creates such an
effect.
Leeward - On
the side away from the wind. (Opposite of Windward)
Leeward
End -
Leeward
Helm - See Helm
Leeward
Mark - The mark that terminates the second reach and/or the run and
that initiates the second or third beat.
Leeway - The
draft (or angle of drift) of a boat to leeward as it proceeds forward.
Lift or
Lifting Shift - A shift in wind direction away from the direction in which
the boat is sailing.
Lifted
Gybe - The gybe that is affected by a lift, which requires a boat,
in order to retain the same sailing angle, to deviate away from the median
downwind course.
Lifted
Tack - The tack that is affected by a lift, which permits a boat to
point closer to the median wind.
Light
Air - Airflow with a velocity (for models) of less than 3 knots.
Loose-Footed - A
fore-and-aft sail not attached to a boom except at the ends.
Lower,
to Sail - To sail further away from the wind.
Lower
Airflow - The airflow at the surface; backed and slowed compared with
the airflow above it.
Lower
Stays - See Baby Stays
Luff - The
leading edge of a sail, fastens to the mast or jib stay.
Luff
Allowance – The material in excess of a straight line added to the luff
of a sail.
Luff,
to - To deviate toward the wind.
Luff
Rope - A line sewed onto the luff of a mainsail so that the luff can
be fitted into a groove in the mast.
Luffing - (1)
Altering course toward the wind.
(2) The
technique by which a leeward boat forces a windward boat to windward.
Lull - A
brief reduction in wind velocity.
Mainsail - The
largest sail on a yacht. The luff is attached
to the after portion of the mast.
Mark - An
object the sailing instructions require to pass on a specified side.
Mast - A
vertical spar used to hoist the sails.
Mast
Crane - A masthead fitting.
Mast
Step - A deck fitting which locates the mast in one or more
locations.
Match
Race – A race in which two boats compete only with each other.
Median Wind - The wind that
flows at the median direction, midway between the extremes in the range of its
oscillating shifts.
Middle - A
position near the rhumb line.
Moderate
Air - Airflow with a velocity (for models) between 3 and 9 knots.
Moment
of Inertia – The resistance to change in the rotation of an object about
its axis.
New
Wind - A wind from a new source that appears during or following the
presence of another wind.
Obstruction - A
mark, a right-of-way boat that must be avoided, a disabled boat, or water too
shallow for sailing.
Off the
wind - To sail downwind.
On Port (or
Starboard) - Sailing on the tack specified.
Optimal
Sailing Angle (Running) - The sailing angle that permits the greater progress
downwind.
Oscillation
or Oscillating Shift - A wind shift that will be followed by a
shift back to the original direction prior to the completion of the leg.
Out of
Phase - A boat sailing downwind is said to be out of phase if her
main boom is deployed on the windward side of the boat.
Outhaul