We successfully financed a 40 year old boat with Lightstream (subsidiary of SunTrust, which is now something else - Truist, maybe?). Anyway, their limit is $100k, and the rate wasn't stupid.
They have very high credit requirements (basically need pristine credit & good income), and they don't actually take a
security interest in the boat (i.e. they don't take a lien) - which seems nice, until you realize that this means you can't deduct the interest.
But, they seem to be one of the few options around for 20+ year old boats.
For insurance, we went with BoatUS - no problem underwriting. Someone else (honestly don't remember who) offered to underwrite, but once they actually reviewed the
survey they came back with such a ridiculous set of required fixes it was obvious that they didn't actually want to insure the boat. (E.g.
surveyor said "couldn't verify
compass light worked in bright sunlight, recommend verifying functionality in the dark;" insurer said "replace the
compass." That was probably the most ridiculous one, but there were a whole string of stupid corrections they wanted done "within 10 days.").
I sent BoatUS the
survey with a written plan of how/when we were going to correct the actual problem items, and they underwrote it without even a question.