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Set the halyard tension so as to remove the HORIZONTAL wrinkles immediately
behind the luff tape. Now look at your sail from the Windward bow sighting aft,
the draft (deepest portion) should be 40% of the chord line (horizontal
distance from leading to trailing edge of sail.) This, then, would be your
light to medium luff tension position. Mark your halyard position with tape or
magic marker.
Now increase the luff tension until a Vertical tension wrinkle develops
immediately behind the luff tape. Ease off slightly until the wrinkle
disappears. Look at your Genoa. The draft is now 35% aft. Mark your ha1yard
This, then, is the heavy air setting.
As you become more familiar with this procedure you will soon be able to
"eyeball" the draft and be well on your way to obtaining optimum Genoa
performance.
Trimming the Genoa
There are two basic considerations in Genoa trim. One, the movement of the jib
leads fore and aft; two, the movement of the trim point in or out in
relationship to the boat's centerline. (Many cruising boats do not have in- or
out-board adjustments as is more prevalent on the smaller one-design sailboats.
First and foremost, the system for setting your jib lead position properly fore
and aft is relatively easy.
Bring your boat on the wind. Trim your Genoa sheet in. Now bring your boat up
into the wind very slowly. If the luff breaks first at the upper portion of the
Genoa, the leads are too far aft. If the luff breaks first in the lower portion
of the sail, the lead is too far forward. When your lead is properly located,
the Genoa will break evenly along the entire length of the luff.
If the athwartship (in and outboard) position of the jib leads are adjustable
we suggest light air settings of 8 to 9 degrees off centerline. Medium air
settings of 9 to 11 degrees, heavy air settings of 11 degrees plus.
This in and outboard movement of the jib leads has one objective, and that is
to accelerate the smooth flow of air aft over the leeward side of the main. The
effect thereby created is known as the "slot effect." The lighter the wind, the
more closed the slot should be made, causing a Venturi (squeezing) effect and
accompanying acceleration of air aft. Conversely, as the wind increases, the
slot is opened reducing the velocity and minimizing the tendency of backwinding
(deflecting air) into the main.
Use of the "foot cord" is basically an "eyeball" function; The foot cord on
your Genoa is readily adjustable by means of a mini "V" jamcleat affixed to the
tack of the Genoa. The simple rule to follow in setting foot cord tension is to
increase tension until the lower foot "stands up" in uniformity with the
remainder of the Genoa.
As a general rule you will need more tension going upwind, easing off as you
bear off the wind. It is normal to see a slight cupping or "end plate" effect
in the lower two to four inches of the foot.
