I went to USAA out of boredom a decade or more ago... filled in 50k for a loan and got my answer within seconds. Anywhere you go, it is a boat... expect a higher than what you think it will or should be interest rate. Plan for the worst, hope for the best. Figure what you can easily afford, and stay 10-25% under that. Don't say you plan to put down 5%, because that is all you can afford, plan to put down $0, and then put down what you can, and leave some cash for "play"...i.e. new life jackets etc, because the last thing you want to do is buy this new boat and then not have the money for gas and stuff you need to get her fixed up the way you want....and that amounts to CC debt you did not factor in.
It is easy, it is doable, just get what you can afford, no more. Tons of boats out there... many I wish I had gotten instead for half the price, but, I am still inside the budget I planned.. heh... many do not stay that way due to bad planning.
A credit union is good too, but places like USAA loan up to 100% of the NADA value, so... for instance, if nada's website says the high end value is 50k, you can borrow up to that... and if you get it for 39k... well, then you free your cash up to make a couple early payments or get her spruced up.
R