Again, thanks to everyone for the ideas. No, I hadn't considered the importance of crew position during the tack, but having heard it, it makes a lot of sense. Also, timing the tack in conjunction with the waves wasn't on my radar, either.
Now I can't wait to get out there again and experiment!
BTW, my max speed yesterday was 19.7 mph. Is that about all I can expect from an '88 Prindle 18?
Kevin