In the little cabana by the Swan/Dolphin pools there is a guy there that sells 100% natural tanning oil. I think it is called black pearl. 26.00 for 8 ozs.
No sunscreen containing oil and othewise is "environmentally safe" if what you are seeking is a sunscreen that the natives will let you apply when snorkeling around their coral.
For that, I suggest treating long-sleeve T-shirts and other clothing with RIT Sunguard, which is a wash-in sunscreen that will make the T-shirts SPF 30. Here is a link for more info:
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