I use Mary Kay Sun Essentials Ultimate Protection Sunblock SPF30....It's UVA and UVB protection and fragrance free........have had no problem with it in Mexico. If you want more info. contact me and will assist you.
Actually you must use an eco-safe sunscreen for ANY of the reefs when snorkeling or swimming. Most commercial sunscreens are toxic to the marine life found of the reefs. You can buy what you need on the web or email me and i'll tell you a great product I use.
What was the great sunscreen product to use that you were referring to. I plan to do the Stingray City Tour in Grand Cayman in a few weeks and I would think they would want me to use the eco-friendly sunscreen there as well.
The eco-friendly products i like best are made by a company called Caribbean Pacific. Their website is www.cpskincare.com. They have a nice selection for both adults and kids. Besides be eco-safe they are great if you have sensitive skin.