I have personally never been exposed to a successful boat exchange or even heard of from anyone else I know, and I know hundreds if not thousands of fellow boaters personally.
On the surface, it appears to be a novel concept; however, when risk/reward is taken into consideration, thats when things break down. Even though $$$ isn’t exchanged, you need a well detailed legal agreement defining obligations & liabilities of both parties & legal remedies when things go wrong (No, I am not an attorney!). Then consider the complications of enforcing that agreement, especially when the parties are not in same state. Both parties would need to review & sign off on inventory onboard , boat condition, & damages (if any) before & after. What are you going to do if someone goes hard aground causing thousands in damage & lengthy layup for repairs? Details of who is going to thoroughly clean, refuel, & pump out holding tank. The need to inform your insurance company & marina/yacht club with possibility of denial or increased rates. And personal acceptance of “do you really want someone else using your boat?”
These things can’t be addressed with a handshake. I agree with
@capta that, all things considered, it’s probably better to charter a boat at a location that you would like to cruise after thoroughly vetting the quality of the company & it’s boats. I was fortunate to do business with an excellent charter club in Pensacola for five years; great people & well maintained boats, so I had first hand experience with the operation. It was costly; and, I had to have charter insurance with defined deductibles in the event that I damaged the boat. Fortunately that never happened!
Having said that, seems that I did read about an exchange program (online), years ago, that was trying to startup. As long as all your bases are covered legally, you’re willing to accept the potential problems that could occur, and finally willing to allow a stranger & his/her guests with unknown experience use your boat, then go for it!