One thing I'll add is that if that I'd make sure the group you are going with realizes this is nothing like a cruise and the only similarity is that you will be sleeping on a boat.

If you are going to spend a couple nights at Leverick, I'd recommend two things. 1) The Friday night BBQ - it's a fun time with good food, band and Jumbies! 2) Rent a car, tour the island and do dinner at Coco Maya.