Is It Safe To Swim In The Ocean?
Beaches on resorts typically have color-coded flags to let swimmers know the relative swimming safety. Public beaches with lots swimmers usually have lifeguards on duty. Some beaches, like Cayo Coco and Cayo Guillermo, have a reputation for tranquil water and good swimming conditions.
Because Cuba’s beaches sit on the Caribbean, sharks are sometimes in the vicinity. This is part of the reason it is inadvisable to go swimming in the early evening or at night, when sharks tend to be the most active. There are also jellyfish in the water, so keep a good lookout.
The biggest concern at Cuban beaches is keeping your valuables safe while you're in the water. If you leave your belongings on the beach while you swim, you run the risk of having them stolen before you return. Leave anything of value in your hotel room's safety deposit box before you hit the beach.