Do whatever it takes to protect yourself from the sun! If you need to wear a shirt in the water -- do it! However, most companies ask that you wear a life jacket while snorkeling, so that will give you some coverage. Just remember, the people you are worrying about impressing while snorkeling, won't be there when you're nursing a sunburn! 8)
__________________
Darlene
Mariner of the Seas
Carnival Magic Bloggers Cruise 5
Mariner of the Seas
HAL Statendam Alaska Cruise Tour - 09/09/12; Disney Magic - 12/01/12; Allure of the Seas - 05/26/13