Piper, that 10 hp or less was done a way with many years ago, and it was under 10 hp, that why the started making the 9.9 because when the under 10 hp law was in effect was when sail boats didn't have to regester if under 10 hp,i've seen drift boats get nailed for haveing a electric on them in the snoqulmie, personal water craft have to be registered and there under 16 ft,