We were on the Navigator in May 2003 and had a wonderful time on the ship. The weather was very iffy the week we happened to go (late May). The comments by others on the board regarding cool sea temperatures are accurate.
If you enjoy homes and history, we recommend taking the Historic Bermuda house tour. It was excellent, informative and a lovely way to see some beautiful homes located in different parts of island. This tour is offered by RSSC.
We also very much enjoyed going over to the Royal Dockyards. If you don't mind a short walk, we advise skipping the RSSC tour and save your money. It is very easy to catch the local ferry in Hamilton very near where the ship docks. The ferry takes you to the Royal Dockyards and you can visit the museum and grounds on your own and at your own pace. The museum charges a modest fee. Be sure to see the dolphin pools as you walk towards the museum.
Our friends who live on Bermuda told us to be sure to do the private boat tour of Nonesuch Island. We were very much looking forward to it. Unfortunately the ship cancelled the tour the night before because they didn't get the minimum number of passengers to sign up.
Based on our experience with the tour desk aboard the Navigator, I advise passengers to check back frequently with the tour desk on board concerning the status of the tours. No point being disappointed by last minute cancellations.
The Williamsburg tour is great fun. We did the deluxe tour that included lunch. It is a long day, but we had an informative tour guide. In Williamsburg, be sure to go into the court house for the mock trial. And if you are "hair challenged" like me, stop by the wig shop and converse with the wig maker for a laugh.
For serious golf addicts, consider playing the course at the Williamsburg Inn in lieu of doing anything else that day. It is beautiful. I played it when I stayed at the Williamsburg Inn on another trip. You would need to make arrangements in advance, including getting there to allow enough time to get your round in.
One last comment, if RSSC again offers the free pre departure stay at the Waldorf, we found the front desk was very amenable when we asked (nicely) for a high floor corner room. Our room had spectacular views of the Chrysler Building as well as the East River.
Have fun.