I want to book a shore excursion(no snorkling) for someone cruising on the Serenade of the Seas next spring. What would be the most interesting thing to do on Antigua, Barbados, or St. Lucia if I can only pick one? I appreciate your help!

In Barbados you should do the cave trip. The cave itself was neat and then we went to a botanical garden and had time to wander the grounds. Driving through the countryside to get there and back was also nice.

In St Lucia, we hired a private guide and he took us all around the island plus we stopped at this awesome restaurant on the top of a hill over looking the coast for a terrific West Indian buffet lunch...Very famous place-
We suggested it, not the driver..but he was able to get us reservations .

In Barbados, we got together with 3 other couples and hired a private sailboat for the day...FANTASTIC!

In Antigua I highly recommend booking a tour with Lawrence of Antigua. We had an excellent day with him - saw a lot of interesting historic sites and great views. His website is:
www.lawrenceofantigua.com

I highly recommend www.jungletoursstlucia.com. These people were great, bot for the faint of heart! They pick you up in an open jeep. You can travel up and down paths that other tours cannot travel. You will really see the real St. lucia and all of it's beauty. Check there web site out and see if it is for you. Antigua we loved Dickenson's Bay for the beach. A gorgeous beach.