sorry it took so long to get back to you. i bet you were REALLY wondering the answers to those questions. well, i hate to make you wait any longer...
it's my second year sailing- 6.5 and 8.5 in 10-15 knots. no idea what kind of weeds. last year i didnt run into a lot of weeds, but when i was a kid sailing there it was crazy weeds. they're out there i'm sure, and i kind of just wanted to have a weed fin in my gear bag just in case. as far as submerged rocks- only wave breaks when i go to lake erie, and they are easily avoidable (knock on wood). most of the time i sail in paradise... PITTSBURGH PENNSYLVANIA!!!