If you’ve ever watched a serious sailing race you’ll notice everyone working all of the time. That is not me. I’m more of periodic check and maybe, just to keep up the image, adjust something, or not.

Sometimes performance was better and sometimes not. Recently I read an advert for Don Guillette that said his products told both how and why adjustments were made. Light dawned; all these years and I can tell by intuition but not by reasoning. So I thought about it a while and surprised myself that I had a theory. As luck would have it Kevin of Port Royale asked if I’d participate in a fun regatta. They needed boats and would provide an experienced crew. And I had a theory. Perfect.

A race. Ah, a chance to score another last place. Quality Time is a good old boat, a late 70’s vintage Catalina 30, overweight, and with a tired mainsail. Per a really good sail maker, Sam Heck, “that main was tired 10 years ago, and no it was not worth re-cutting a 20 year old sail”. I wasn’t delusional enough to think of winning, I merely hoped that the boat retrieving the markers didn’t question if we were part of the race. Yes that happened a few years back.

Race day, after poor starts, actually finished mid-pack in both races. The theory actually worked! Better, it was simple to explain to crew what was needed.

Disclaimer: I’m no expert, certainly not a racer. This just describes my thoughts when I get around to trimming sails. Love to hear yours.

The Theory: Keep her on her feet.

Why?: When she heels beyond her designed lines, she’ll slow due additional surface friction. But worse, she’ll present a shape in the water that makes her turn. You have to apply extra helm to keep her on course. This extra rudder angle acts as a brake. Called too much weather helm. Consensus: over 3 degrees of rudder angle is a brake. Pending the hull, this starts around 20 degrees of heel.

You counter heeling in 2 ways; moving crew to the high side. Further out is better. When that fails you adjust sails to reduce power.

Easy enough, but QT has 19 lines for adjusting power. Maybe not so easy.

Powering up: Going upwind power is derived from lift. As you turn downwind power derives from drag. So adjustments must differ. Lift is a lot more powerful than drag.

Lift power is derived from angle to the wind. This is the primary adjustment. All others are refinements. “When in doubt ease her out; when she luffs trim her in” works really well.

Depth of sail refers to the curve or shape. More depth adds power up to the point that the wind flow separates. At that point lift is partially replaced by the weaker drag. The sail is said to be stalled. More sail twist makes the upper sail power stronger. Ease mainsheet until the top tell tale flies. This is the tale the tell tales are telling. All flags flying says the angle and depth and twist are pretty darn good: maximum power. As course shifts to a downwind run the tell tales become useless.What to do? She’s still heeling too much and weather helm is worse. You know you need to reduce power. Read on.Beam force is bad. All that power is applied at the point of maximum sail depth in a direction perpendicular to to that spot. Some component of the force points forward and some points to the beam. Beam force is heeling force. As you fall away (from wind), the forward pointing force grows. This is good.You like forward force. As it turns out the maximum depth should be somewhat forward, 40% is often mentioned. This adds forward force. Stronger winds blow max depth aft. To correct, tighten any line that stretches the luff. Traditionally by the halyard, though a Cunningham seems more effective.
Falling off works perfectly well. That’s when footing occurs. You’re trading a shorter distance to that upwind mark for faster speed over a longer distance. You’re hoping to make up the difference. That’s for racers. When the admiral is aboard you’re gaining both speed and a happier admiral.Powering down: If you must hold course then follow the Flatten, Luff, Reduce sequence. Again the tell tales tell all.
Flatten: On the main the lower third flattens by pulling the outhaul. The upper portion depends on the type of mast you have. If it’s a telephone pole like Quality Time’s, relax, there is nothing you can do. Those with a fractional rig (means mast can bend) hauling on the backstay adjuster flattens it.The jib’s outhaul equivalent is the angle of jib sheet to jib foot. Straighter angle flattens lower third. Unlike the main luff, the jib luff can curve outward producing more power. To de-curve the luff haul on the backstay adjuster.Less twist stalls the upper sail producing less power. Tighten mainsheet and perhaps the boom vang.Luff: Ease the main out preferably by traveler. It is OK to luff and to backwind the main. QT’s tired main is stretched so luffing happens. As long as those flags fly and the leach is not flapping it’s good. She’ll be on her lines and will move along nicely. Don’t luff the jib.Reduce: again, the goal is keeping her on her lines. To that end, furling a jib or reefing the main work equally well. Either produce less beam power.How does downwind differ? Downwind is all about max drag. Big deep rounded sails. As we sail higher the sail’s curve gets far less and a slimmer triangular sail is better. This is why racers ease the halyards and outhauls and backstay, they are emulating that big deep round sail. Broaching – a traumatic experience – is beam force which was the culprit causing weather helm. Keep her on her feet remains the goal.
Beware that very light or very heavy winds have additional considerations. Bumpy seas may need more power. I once wasn’t able to generate enough power to tack in one foot seas.

Old Sails: Just can’t point as high; however off wind their deeper shape can help as the power direction is more forward and likely more powerful. Luffs are longer so a Cunningham helps a lot. Leach twist is problematic as the cloth doesn’t stretch in proportion to the luff or foot. So not much twist.