There's plenty of outfits willing to charter you a boat, your biggest
concern should be what happens once it's in your hands...

Actually, unless the guy has a reasonably verifiable boating resume there
aren't.

Fortunately, you can't just take off in a 50-foot, 40,000 pound, 800 horsepower
machine from most charter comapnies without doing a reasonable job of
convincing the management (and often actually demonstrating) you have the
capacity and experience to handle it.