Most cruises sail between November and April to avoid the possiblity of encountering storms, choppy seas and hurricanes which are more likely in the summer months. Eastern Caribbean cruises would call on ports such as British and US Virgin Islands, Bahamas, Dominican Republic and Western Caribbean ports may call on Grand Cayman, Cozumel, Belize. Southern Caribbean cruises tend to be longer stopping at US Virgin Islands, Barbados, Grenada, Dominica to give an example. It all depends on what islands you are interested - most cruise brochures give information on their porst of call or information is available on the internet. You can take a longer cruise and cover all the areas if you can't pick a favourite!
December through mid-April is the best time to visit the Caribbean. Each island is beautiful I'm sure but I can only recommend the ones I've been to of course. Don't miss St Lucia for the Grand Pitons, Botanical Gardens & Sulphur Springs. But my favourite above all is Antigua - it has 365 beaches so you're always able to find an idyllic white sandy beach to have to yourself!
The best months to visit the Caribbean are November through to April. You are definitely guaranteed warm weather and cloudless blue skies. If there does happen to be any rain, it is over before you know it and leaves everywhere feeling fresh. All the islands in the Caribbean are fabulous although they do have many similarities. Martinique was one of my favourites with the rainforest and Botanical gardens. St Lucia was a lovely port to cruise into and much to see. Willemstad was a very pretty and colourful town and the dolphin encounter a must. For relaxation, palm trees and beaches it has to be Antigua.