Ok, I know this topic will be as volatile as global warming, but those who have been traveling to the Caribbean for a long time like myself would agree there have been some pretty dramatic changes under the water. This link may give a little insight to why:
We’re Hurting Our Coral Reefs Trunk Bay in 1979 when I first visited, and Trunk Bay today is a different place. Is it the amount people that visit daily or is it the lotions that are sprayed/rubbed in beach side that has caused these changes? Probably both is the right answer, but one can be easily corrected and that is the later.
As someone who truly loves STJ I would ask all who visit or live on island that they consider being part of the solution - please apply goops, gobs, and God forbid those awful sprays at your villa, hotel, or cruise ship stateroom. Pay attention to products listed in the link and avoid them if possible. Once again I do realize too much sun is dangerous and I truly understand the use of sun protection products are important, but there is time and place for them. However on the beach is neither the time nor place. Apply and rub them in well before you arrive on the beach. They will have time to absorb into your skin and you will get better protection and the coral will say thank you.
If you are having a hard time getting you head around what a little spray/lotin is going to do to the ocean look at this way. You have a nice white cement driveway when someone pulls in leaking oil. They leave after a short visit, but the 10 drops of oil leaves a baseball size stain on your driveway. A few drops of oil is not a big deal... or is it? Now think about the number of people who pull up on the beach of Trunk Bay weekly.
Me... I do not use the stuff. I wear a shirt, wear a hat, and sit in the shade. I get plenty of color and never burn. Being a red hair boy by birth of French/Irish descent I can tell you without protection I would be trouble. The beaches of STJ offer some amazing shade and it is a valid option.