We rented a car ourselves for $60 and drove around the island, stopping for lunch. It was extremely hot and humid so it wasn't pleasant. The island is beautiful, though. We did some shopping in the hour we had left.
No cruises added
We went on the Bacardi tour which was good and did a "city tour" but we couldn't see out of the bus very well and it was dark on the way home. We were only given 20 minutes at the fort at that was NOT enough time.
The beaches were great. We walked around the entire area and got some very nice photos. We never went in the water but enjoyed sitting by it in a shady chaise. The music was a nice touch and the BBQ was quite decent.