each class has a "build" but with the open box boats you have a greater range. This I believe is due to the rules allowing rig variation and thus power...

The top Laser guys I recall tended to be tall.. They hike and long legs means more leverage.. Mothies are average build.. Star guys are just big period.. Forbes is/was 6'6? and 50 inch chest massive guy.. I was a kid so my memory could be faulty