February 1, 2016 “When sailing downwind at an angle where there is flow across the mainsail, is it faster to ease the main just short of luffing (reducing angle of attack), or trim it in just short of a stall (maximum angle of attack)?”

David Flynn

December 8, 2015 Quantum Expert Answer

It is always faster to be slightly under trimmed than over trimmed on the mainsail downwind. Obviously we all would like to have the perfect trim 100% of the time but this is very hard to achieve. A recommendation is to lean toward the main that is just slightly luffing. Look for the bubble that will begin to form around the luff near the first spreader; this will keep you fast and on your feet. The over-trimmed main does not utilize its full potential as far as optimum shape for speed.

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