Join Date: Jun 2005
Location: New Orleans
Thanked 41 Times in 38 Posts
Rep Power: 11
If everything's roughly symmetrical in your hull, straightness and plumbness of spar, sails, and weight distribution, then the conditions you're sailing in may be the factor. Double-reefed in heavy wind, seas, and current may not the best time to compare performance this way. The angle of the current (if not truly head-on), shape and angle of the seas, and difference in wind gusts can make a difference you're not aware of (assuming you're using GPS to get speed readings).
I've often found in sloppy conditions that sometimes one tack is just "better" than the other, in a boat which otherwise sails the same close-hauled on either tack. Try your boat in lighter air, no-reef, no current conditions if you can find them, and see what happens then.