I'm running around like crazy this week packing FI and I for our trip! I went to Mexico a few years ago and did a snorkeling excursion. They wouldn't allow me to wear my regular sunscreen - it is very harmful to the coral reefs. I'm a redhead and need to reapply my sunscreen alot! I got burned so bad I looked like a little lobster! I can't risk that again with my wedding on this trip :)Here's some info:
http://www.puertovallartatours.net/biodegradable-sunscreen.htmAnyway, most snorkeling excusion people will not let you take regular sunscreen with you - you have to have biodegradable sunscreen. I've been on the hunt for this in the store and did a google search to see what brands I need to look for. I know you can buy the biodegradable at the resorts, but they jack up the price.Here's what I found off tripadvisor.com. Hope it's helpful for you too and we can help save the coral reefs :)They [the tour guides] do check, and your non-biodegradable sunscreen will be confiscated if found. Chemical Free and Biodegradable are not the same thing. You will need it to clearly say Biodegradable on the label. Hawaiian Tropic should be acceptable - only the blue bottle with "Biodegradable" on the label, not any of the other kinds. Brands that are eco-friendly and biodegradable include Caribbean Sol, Cactus Juice, Mexitan, BATAB, UV Natural, Smartshield, and Kiss My Face. Brands that may get you through the gate, as they are biodegradable, but contain chemicals known to damage coral reefs, include SafeSea and Nature's Gate. Brands that are just plain bad for the marine environment include Banana Boat, Coppertone, No-AD, Hawaiian Tropic (except blue bottle), and Panama Jack.