Cover your skin up. As a diver, I spend a lot of time in the sun. Consequently I sometimes get tanned. But more frequently, I get burned. Either way, there is the same end result: freckles, wrinkles, and the threat of skin cancer.
I didn’t always, but I wear a hat now. And cover up the skin. And wear SPF.
However, I don’t always recommend wearing sunscreen before diving. DAN explains that “chemicals found in non biodegradable sunscreens may ‘awaken’ dormant viruses present around corals. These viruses can replicate rapidly, killing the corals’ symbiotic algae and causing coral bleaching.” (quoted from Alert Diver, Spring 2012 issue, “DAN Medics Answer Your Questions”.
It might seem inconsequential. One person diving with sunscreen. One person swimming with sunscreen. But of course we know that it is never just ONE person, it is usually many, and sometimes too many. Again, I call for a minor change in our behavior.
Cover up with clothing, hats, and sunglasses. My rash guard offers sun protection before my diving. and after diving, you might find it necessary to douse yourself with SPF (I do, again with the sunburn). So look for biodegradable brands like Badger SPF 30 Sunscreen For Face & Body 2.9 oz (87 ml)
or anything containing a mineral ingredient. (Titanium oxide, zinc oxide, etc). No one is claiming that these won’t do damage to reefs either, but they’re not known to cause environmental damages (yet).
Maybe not the best answer to give, but just tossing some general awareness in your direction.
What’s bad for the ocean is bad for us all. Do your part.