Back from the Explorer 3 days ago (Sunday), and wanted to do a really quick review. We had a fabulous time!
The ship is in wonderful shape; it's just beautiful (our second time on it). The food was teriffic (in the Windjammer and the Dining Room), and the service was fantastic.
As for the ports:
San Juan- we just walked around Old San Juan and shopped. We really enjoyed it and felt 100% safe, even when it got dark.
St. Maarten- did a little bit of shopping and the Rhino Rider excursion. It was pretty good.
St. Thomas- did the Godfrey Tour and had the best time. He was waiting for us on time. I would highly recommend doing the island tour with Godfrey. For a mere $20 he picks you up, drops you off downtown in the shopping area, then takes you on a tour of the island. He then takes you to your choice of beach; and picks you up afterwards to take you back your ship. Not to mention, he is very respectful and the nicest guy ever!