We were re-routed to Key West in October, 2000, and they had plenty of excursions offered. Probably not as many as the regular ports of call, but it seemed that they had a good contingency plan ready. We actually were originally going to call at Nassau, too, and they had booked excursions there. In the end, the storm weakened and turned south, so we went to St. Thomas. The Nassau excursions were refunded to our account.
We went on the Fury Catamaran snorkeling excursion on Key West. If they offer this for the western itinerary, I highly recommend it if you're a snorkeler. The catamaran takes you about 7 miles out to sea and anchors off a reef for a few hours. There's free drinks on the trip back.
