We are going on a cruise to the following islands: St. Thomas, Dominica, Antigua, Barbados and St. Lucia.

We already have plans for St. Thomas (taking the ferry to St. Johns and renting a Jeep) and Barbados (island excursion) but not the rest. Dominica - Does anyone know the Must-sees? I know it's known for hiking and diving but is the snorkeling worth the time. What about tubing? (not usually a big fan but I heard there's a great river for this here?)
St. Lucia - any particular sites we should not miss?
Antiqua - Do they have better snorkeling here or in Barbuda? Best beach for relaxation and few drinks?

Thanks in advance for your help!

Dominica has so many things to do - snorkeling go to Champagne Beach or the Scotts Head Marine Park. Interested in history? Visit the Cabrits National Park in the north of the island. Nature? The Fresh Water Lake is a fabulous place with a completely different climate and weather system, and also has kayaks for rent. Trafalgar Falls is a must do - stop at the River Rock Cafe for lunch. We had a phenomenal driver/guide, Peter Royer, tel 767 448 5031.
St Lucia is like Dominica in being very mountainous and lush. Check out the Soufriere area with the drive through volcano.
And in Antigua, Nelsons Dockyard is a must do. Lots of nice beaches on Antigua, check out Dickenson Bay.

Thank you Bajangirl, this is very helpful! Would you suggest the falls over the others though if you only had one day?

If your Barbados excursion is in a large group in a bus, you will not enjoy it nearly as much as hiring a taxifor the day and getting a personalized tour. Highlights are Harrison's Cave, Flower Forest, Francia Plantation, wildlife preserve, and historical buildings in Bridgetown. Try lunch on the beach at the very classy resort, Coral Reef Club.

Thanks for letting me know. I heard Harrison's Cave is closed. Does anyone have additional info about this?
Also, does any have any tips on great snorkeling locations (besides St. John) in any of these islands? Lastly, how easy/difficult is it to go to Barbuda from Antigua for snorkeling/beaches and is is worth the trip?

Many thanks!

On Barbados, there is an underwater park next to Coral Reef Club where you can snorkel.

Yes, Trafalgar Falls in Dominica if you're just doing one thing - definitely.
Also, in Barbados, Harrisons Cave will be closing at the end of May til year end, Francia Plantation has changed ownership and is no longer open to the public. However, George Washington House is excellent and near to the port.
Enjoy.

In dominica see if you can do whale watchng. it was phenomenal and barbados harrison caves if it's open

Glory Tours informed me that Harrison's Cave is closed so unfortunately I will not be going there. Any snorkeling and/or beach spots that should not be missed on these islands?

Thanks all!