Jardines de la Reina is an archipelago in the south of Cuba. It has the best scuba diving in Cuba, as well as a great ocean fishing. There is also good wreck-diving with old Spanish ships. Shore and seabed: sand, stones. 
In most cases the best is to take a weekly package tour as following. Fly to Havana Airport (HAV) (not included in the package). Take a ground transfer to port Jucaro. Next you'll have a "dive safari" during 6 days.