My family and I are taking the 7 day cruise next Saturday which stops in Tortola and St Thomas. We'll have our 6 year old and our 8 year old with us. Other than hitting the beaches at both spots, are their suggestions for other things to do? Would it be worth our time on St Thomas to rent a car and to drive around the island for the day? If so, where should we go? Would it be better to take the ferry over to St John's and rent a car there?

Thanks for any ideas and suggestions!