If you can be on a lake in a boat, you can do a boat in BVI. Especially a Cat as much less motion. My suggestion for the novice is to do sea sickness prevention medication for 1st 2-3 days (beginning on flight down) such as scopolamine patch, which lasts for 72 hours. With this, I have never had anyone not enjoy being on boat in protected waters of the BVI.

I would agree with land based being Virgin Gorda and a day trip to Anegada or to Jost. I don't think I would try 3 islands in a week.