I think I get it. It's not about the efficiency of forward motion verses heeling motion in too high winds. It's about the efficiancy of sailing into the wind. A flatter sail can point higher and sail closer to the wind. A cruiser will want to sail into the waves for comfort and safety, if leeway allows, and a racer will want better options for most efficient heading to get ahead.
-Will
Not exactly. Whether you race or cruise, it's ALWAYS better to sail with good sails and proper trim.
If sails are stretched and baggy, they cannot sail as efficiently, and will cause more heeling. Sailing with proper trim and angle of attack also reduces flogging for under-trimming, and heeling for over-trimming.
Also, when close hauled, good jib shape makes steering much easier. That being said, there is a difference in racing cut sails, or cruising cut sails that will allow for easier steering on the wind. It's kinda like the sweet spot on a baseball bat or tennis racket. Cruising cut sails may not point quite as close, but it's easier to steer "in the groove" with a "larger" sweet spot, and racing cut sails require far more attention to steering as the sails cut more of a knife edge.
Proper rig tension helps a lot as well. I have been sailing with less rig tension than I want, which is more about structural problems in my 30 year old mast step. The loose forestay allows the luff to fall off, creating effectively more draft. When it's gusty, it makes steering and keeping telltales flying difficult, and it's like the luff kinda flaps around and catches the wind. Ugh. Last Fall, we had much gusty and shifty NW winds. At our lake, it required a lot of beating, but at the same time, gusts would lift, and just slam the boat. It's not all that enjoyable sailing, and it was even worse with my loose rig.
This year, my friend with a Catalina 22 Sport added an adjustable backstay to the masthead rig. It was a surprising improvement; as the breeze picked up, and we pulled on more backstay, the reduction in forestay sag noticeably depowered the genoa.
Of course, an adjustable backstay on a fractional rig will reduce luff sag, but its more immediate effect is to bend the mast forward, which allows the convex cut of the luff of the main to follow more of a curve, which reduces camber and de-powers the main. I should explain: the luff of the sail is cut with some convexity. When the luff is pulled straight (as tightening the halyard pulls the head and tack) this convexity forms draft in the sail. If the luff is not pulled straight - if it allows the convexity to push forward - that flattens the sail. For this reason, an adjustable backstay on a fractional rig is one of the most important tools to de-power the main, while secondarily reducing jib luff sag and flattening and depowering the jib.
