water shoes are neoprene shoes worn under swim fins or for use in water where you don't want to get your shoes wet and have to walk around in them all day, They can be purchased on the ship, they are almost required footwear if you are climbing Dunn River Falls on Jamaica. No, they are not needed if you are swimming, and they are not if you are snorkeling,diving, etc. They are just nice to have if you are wading in coral etc. A lot of the beaches in the Caribbean are sand and coral mixed.