North American Yachts Yacht Owner's Manual - page 13
13
The MAIN BOOM TRAVELER, available on the fixed keel model, has the primary
function of controlling the point of trim, inboard or outboard, at which the
mainsheet trim block attaches to the boat. The MAIN BOOM TRAVELER should be
used as follows:
Wind:
0 - 5
Set the main boom slightly to windward of the boat's centerline.
5 - 10
Set the main boom at the boat's centerline.
10 - 15
Set the Traveler to the full outboard position. This reduces
heeling and allows the air to escape more freely from the leech
area of the mainsail.
15 - 25
Set the Traveler one-half the distance between the centerline
and the leeward aft corner of the boat.
The Boom Vang is used primarily when the mainsheet is eased and the end of the
boom is no longer in a position where the Main Boom Traveler is effective, (the
end of the boom now being far out over the rail.)
The Boom Vang which is attached to the base of the mast then up to the center
of the boom by means of pulley arrangement provides mechanical advantage, then
basically assumes the function of the Main Boom Traveler.
As the main boom is eased, the boom rises causing the upper part of the main to
twist off to leeward rendering the top 1/3 of the main ineffective. The Boom
Vang then hauls the boom down (not in) causing a uniform leech curve while
making the upper leech once again, effective.
Tell tales located about 25% aft of the chord length along the luff of the main
can also be most helpful. We suggest 3/8 inch streams about 7 inches long of
lightweight nylon taped to each side of the sail. On the average 23-foot boat,
three sets, about six feet above one another, should be ample. When going to
windward with the main trimmed as previously described, if you are sailing too
close to the wind, the windward tell tale will lift and flutter. Layoff a bit
and the weather tell tale will flow aft again. Conversely, sailing too far off
the wind will cause the leeward tell tale to flutter. Bring the boat up a bit
and it will then flow aft.
If you master the above mainsail setting and trimming technique you will be
well on your way toward the most effective use of your new main.
G. SETTING & TRIMMING GENOAS & JIBS
The procedure for setting the Genoa is quite similar to that of the main. Your
Genoa is designed so as to place the maximum draft (deepest portion) of your
Genoa -35 to 50% -aft of the luff, (leading edge.)
Because your Genoa is of the "stretchy" luff (no rigid wire) concept, the draft
is very easily moved forward through the use of luff tension. Conversely, it
moves aft when the tension is eased.
A suggested procedure for having the proper sail set at all times would be to
set your Genoa up on a stay when the wind is 8 - 10 m.p.h.