Zanzibar
While in Zanzibar the water will be inviting for the water sports that the country provides. Snorkeling and kayaking , windsurfing all are available at the coast. There are trainers that will show you how to experience these water activities. There are several companies that will show you how to enjoy your time in the water.
You can learn to scuba dive with qualified dive instructors. There are boats that you can rent for cruising into the Caribbean.