That sounds high to me but it depends on how much your financing too. With boat loans, the more you borrow the lower the rate and the longer you push it out the lower the rate also.
Your best bet is to get the longest term loan you can which will give you the lowest rate and then pay it off early as there is no prepayment penalty.
Most of our loans are between 6%-7% right now and usually the local credit unions can beat our rates.