Two thoughts on the above;
Spinsheet does have an online marketplace, which I think you will be posted if you take out an ad. Most yacht clubs have a old fashioned bulletin board where you may be able to post an ad.
The other issue has to do with Bank Loans. It really created complications to attempt to get a loan as partners. What actually happened is that I took a loan for my part of the ownership and was listed as the owner. My partner paid his share in cash, with his financing coming from other sources. We had a detailed partnership agreement which including the requirement to file a lein on the documentation showing him as the creditor rather than as a partner. The Insurance policy had a rider which listed him in some form as a frequent user of the boat.
Jeff