As a former collegiate rower and sculler (sculler on the side, not much collegiate sculling) I'd say that if you want to be fast you'll essentially copy dimensions from one of the big and successful companies...vespoli, empacher, resolute etc. Even in the amateur ranks you will see very high end boats made from very lightweight composites, fiberglass, carbon fiber etc. I've seen some very attractive wooden sculls but to be competitive...I don't know if that's realistic. My shell was something like 25 feet long and weighed in at something like thirty pounds give or take. That was in the 1990s so my memory may not serve. I'm sure they've gotten lighter since. Could be a true work of art though.