Look at all of the Harley clones. The massive team of lawyers at Harley can't do a thing about it. You can trademark the name, you can patent a unique mechanical device or a unique design but the shape of a boat or a motorcycle would not be legally protected.

I think Nick's comments about why one would not want to copy any boat exactly is on point. Even if one legally can copy a boat design I would think that any boat no matter how good can always be improved even in the slightest way.

Boaters in the 70's used to take off molds directly off of a good boat design. TRUE CLONING. I never remember hearing anything about the legality of it because the boats were never sold but were used by the person taking the mold.