The Hobie 21 can do it. The same guy who did the Drake Passage also sailed from Miami to South America, island-hopping through the Caribbean. Four guys on two Hobie 21 Sport Cruisers. The boats were brand new out of the box and not modified. They were loaded down with lots of bottled water and one of the boats even carried a set of beach wheels.

And Hobie Cat Co. has (or at least used to) a very nice tent for the Sport Cruiser.

I would think it could handle three people easily (although sometimes three's a crowd).