Do you have boat/home insurance? You may be able to work with your own insurer to get the other boat owner to pay? Do you have the name of the boat owner or can you obtain their name? You may be able to obtain the information and perhaps seek out their insurance that way as well.
The above is general legal and business analysis. It is not "legal advice" but analysis, and different lawyers may analyze this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here