St Kitts - Catamaran day sail to Nevis is excellent. Snorkeling, BBQ on the Beach at Nevis etc. Many people go on this trip more than once. Tortola - dolphin swim is popular, but if you want something a little quieter try a trip to the Baths at Virgin Gorda.
St Kitts: just walk off & ask for an island tour. We used to go with Annette. Barbados: get up to St. Johns, a beautiful church overlooking the wild waters at Bathsheba. Town beach of Carlisle Bay is also good, with a beach bar run by a lady from Chester. St. Thomas, give the town a miss, just full of diamond shops, get the ferry over to St. Johns & Trunk Bay, where the Clintons honeymooned. St Thomas has however a great beach, Megans Bay. Pay on entry, $3/$4 I think. Tortola, get to Virgin Gorda, like no other beach I've ever seen. St. Lucia, again just walk off & ask for a local tour of the Island, including the sulpher springs.
Barbados - swimming with Giant Turtles. Incredible experience and suitable for all ages. Don't wiggle your fingers too much though - they're quite short sighted and may mistake you for lunch.
Hello lucky you if you are a bit more independant minded try the big yellow banana tour on st kitts which is available from just outside the dock,around 25 dollars does all island with stops and music and info includes beach,.culture batik centre .tortola has minibuses for all island tour including stop at the top of the world for refreshments and 360 degree view of whole island available outsde dock gates also must try pussers in rhode town if you can beat the crew for a seat try the 98 percent rum.at st lucia taxis are available with a pricelist we went to marigot bay where dr dolittle was filmed very pretty with a hotel,bar ,facilities do some snorkeling buy hats ,fruit baskets,animals being made in palm leaves,this place is an island acessed by a small 1 dollar ferry boat taxi driver will come back to collect you. around 50 dollars for the day . hope this helps have a great holiday .