I can't speak for many water excursions in Key West, but I can tell you what's good in town. If you've never been there and want to get a good overview of the town, take the conch train. It's silly, but it gets the job done. It drives you around town in open air trams telling you about the sights. Our personal favorite spot was the lighthouse and lighthouse museum. The property's been restored beautifully, and you can learn a lot of Key West history there. Right across the street, and also not to be missed, is the Hemingway House. The cats are a hoot, and you should go just to say you've been there. Everyone does. If you want to sail on a large boat, the Western Union is wonderful. It's an old cable-laying schooner. The butterfly sanctuary near Southernmost Point on Duval is also beautiful and relaxing. And, btw, our favorite place to eat was Billie's. Great fish and chips, conch fritters, and other casual meals - and probably the most reasonably priced place in town. It's right off Mallory Square. Super easy to find. The only thing I suggest you DON'T do is attempt to go to the beach. KW is just not a beach town no matter how you slice it. Even the most recommended beach (Ft. Zach Taylor Park) is a huge letdown. Don't pay the cruiseline's prices for any of these things. KW is expensive enough; pay at the door to these places and save a few dollars. Hopefully, other people can offer more insight to water excursions for you. Enjoy your trip!
We enjoyed a walking tour in Key West. It was led by a guide who was very knowlegable on the area, it was a pleasant walk and we got to see the city highlights in an afternoon with time left for food and drink. Also, we once did a sailing trip in key west which was pleasant.
As for Nassau, not much there, we did snorkeling once off a catamaran which was nice. The city itself is the pits, and it seems that almost all Caribbean cruises stop there.
We did the dolphin swim at Blue Lagoon while we were in Nassau. It was expensive, but worth every penny. My kids are still talking about it and watching the video and it was almost two years ago.
Celebrity Century 1/09
Carnival Destiny 10/07
Carnival Destiny 9/06
Monarch of the Seas 3/06
Carnival Inspiration 8/05
Carnival Miracle 4/05
Carnival Inspiration 4/04
Sovereign of the Seas 4/03
I went to the Florida Keys on my honeymoon and visited Key numerous times. You have to go to Sloppy Joe's , it's a great bar with really good food and great music. There's a live cam right outside of sloppy joes the web site is www.liveduvalstreet.com. Another good place is of course Margaritaville (hopefully I spelled it correctly). Mallory square is outrageous at sunset , lots of people , street performers and vendors etc. There was a restaurant that I went to called Crabby Bills , the food was really (shrimp wrapped with bacon is excellent) great and reasonable. I believe they are located on Green Street off of Duval. There's a good web site called www.keywest.com that pretty much tells you everything.