I was on a friend's boat recently and noticed an odd trim condition. There are three sets of telltales equally spaced vertically along the length of the luff of the sail (typical arrangement). The upper and lower windward telltales would consistently fly properly while the center telltale would lift while going upwind or slightly off the wind. We didn't try to correct it but there was some discussion about it at the end of the day. I thought there was an excessive amount of headsail sag. What do you think would cause this type of trim condition?
