If you've signed a P & S which stipulates an arbitrator, particularly a specific arbitrator, then that means that any court, including small claims is more than likely out the window. Any dispute is going to go to that arbitrator. If the P & S was written by the seller (sellers broker) and lists an arbitrator, then that is the arbitrator hired by the seller or sellers broker. Look into the history
of arbitration, for example those used by banks. There is an astonishing percentage of verdicts in the favor of the bank in the case of arbitration. After all, they are the ones bringing repeat business, not you.
I would not go to an arbitrator listed on the P & S. That would be like going directly to the judge. You would want to discuss with a lawyer.
The boat must be a smoking deal to be willing to pay legal fees
on top of purchase price
to take possession of it.
Maybe if you laid down some generic details about the issue??