GUS Sails -- Tuning Guide

Updated February 2000

Thanks for selecting Gus Sails. Remember, a tuning guide simply gets you "in the ball park", don’t be afraid to test on your own!

Mast Rake - Put a tape measure on the main halyard and run it up to the locked position. The tape should read 28’4" to the transom/deck intersection. Try raking aft slightly to depower or forward to power up!

Shroud Tension – You should have to pull on the halyard to get your headstay connected. If you use a Loose Gauge it should read about 100 lbs. If you want to depower the rig, ease tension a little.

Spreaders – Spreader "sweep" affects how your mast bends fore and aft. Less "sweep" gives a straighter mast, more "sweep" means more mast bend. For Gus Sails "sweep" should be set at 2" with 17" spreaders. If you need a stiffer mast (sailing with crew) set the "sweep" at 1 ½". If you sail mostly in light air, set the "sweep" at 2 ½".

If you have shorter spreaders or can’t get the "sweep" forward, don’t panic. Mast bend as a result of sheet tension or vang far outweighs the effect your spreaders have on sail shape.

Outhaul – Make sure the clew of your sail does not go beyond the black band on your boom. You won’t quite be able to take all the shape out of the bottom of the sail. Ease the Outhaul a couple inches to make the bottom of the sail fuller in moderate air upwind. Ease a little more for reaching legs.

Vang – The vang is your ultimate depowering weapon. If you weigh under 170 lbs. and you have an AP sail up, you will use the full range of your vang. At 15 kts, the vang should be all the way on going upwind. You MUST EASE the vang before rounding the top mark. Bigger sailors will use considerably less vang. If you have a heavy air sail up, use considerably less vang than with an AP. Remember use no vang upwind until you start to get overpowered. Downwind use enough vang to keep the top batten parallel with the boom, adjust for velocity changes.

Cunningham – Use only enough cunningham to pull the "slack" out of the luff. When overpowered, use slightly more cunningham. You will have to pull hard on the cunningham only in very heavy winds or with an old sail.

Mainsheet – Generally, use enough sheet to keep the top batten parallel with the boom. When the top batten is parallel with the boom, your batten tel-tale will stall most of the time. Twist the top of the sail open 15 degrees in all puffs, out of all tacks or anytime you feel slow. The MC is a heavy cat rigged boat and constantly needs "help" to re-accelerate. Twisting your sail open is how you accelerate. Trim to normal only when you have reached top speed!

Traveler – If you weigh under 170 lbs, put the traveler 2" down from centerline and forget about it. You will use the vang and sheet to get the boom farther off centerline as you get overpowered. At 14 kts the boom should be over the leeward corner of the boat. At 18 kts, the boom should be 1’ to leeward of the corner. Bigger sailors can effectively get upwind by adjusting the traveler to leeward in the puffs in lieu of vang sheeting. Never sail upwind with the traveler on centerline, it stalls the lower part of the sail.

Downwind - Sail heeled to leeward until you can heel to weather (about 6 knots).

Biggest Tip – No trophies are handed out to the sailor who can point the highest, so DON’T pinch! Bear off, go fast, tack on shifts, and win races!

Good Luck and don’t hesitate to call with any questions.

Bill Draheim