Sail trim

Last weekend we buried the rail on Nomad, sailing in a nice but not overwhelming wind. When the rail went under we were healed nearly 35 degrees, and a couple of things puzzle me. The first is that we were heeled over that far in winds that were not as strong as we have seen in the past. (When Jeff of Gail Force joined us later, he said that the winds had been around 17 knots, max.) The second is that Nomad held her course without rounding up.

I had moved the jib traveler aft, which allowed us to sheet the jib in much tighter than we have in the past. (The traveler track arc matches the widest part of the beam. The aft end is actually several inches closer to the center of the boat.) In fact the sail was touching the stanchion, and I think that explains the heel. It might also help explain why Nomad held her head down. In addition, when I hoisted the main I didn't get the luff pulled completely tight, allowing a bit of a sag or "bagging" of the main. Maybe, having a bit more power on the jib and a bit less on the main, added to Nomad's ability to heel without rounding up?

Another puzzle; even with all of the heel, we (according to the GPS) were not making hull speed. I would have thought we would hit hull speed first, then start heeling over more and more and the sails worked against the keel.

I'm not sure. Even with my aviation background sail trim is still a bit of a mystery. It was sure fun though.

LATER: According to some internet forums...
I have it backwards; tightening the jib and easing off on the main halyard de-powered the jib and powered up the main. Apparently pulling the jib foot tight spills air off the top of the sail. I had assumed that pulling the sails in tight extracted the maximum amount of energy out of the wind when close hauled, but it seems sheeting them in tight keeps one from overpowering the boat.

But I still haven't figured this out to my satisfaction yet.

LATER STILL: Clearly there is a lot to learn about sail trim. One thing for certain is I need to play with the outhaul more. I think I have adjusted it once since we bought the boat, and that's when I bent the main on the very first time.