Quite a few new boat owners lease their boats out to charter service companies to recoup some of their costs. Of course its a lot more popular in cruising destinations like Florida & the Carribean. We have a new charter service here in the Chesapeake, but you would have to research your specific area online. My advice would be to work with a middle man like this, because they will require the renter to have adequate insurance & training. Also, they are generally resposible for maintenance, upkeep, repairs, slip fees, etc. that can really add up.
I see guys lists their boats for rent in local marine trade mags & if or when some idiot wrecks their boat, they'll be sorry if they didn't have a responsibility agreement in writing.