Virtually ever surfer in the world applies sunscreen before they paddle out in the surf. Tragically one of the most common ingredients in most sunscreens is oxybenzone which not only is harmful to humans recent studies have show that it cause deformities in coral larvae, making them unable to swim, settle out and form new coral colonies. It also increases the rate at which coral bleaching occurs.
In 2008, the Centers for Disease Control and Prevention (CDC) reported that nearly all Americans were contaminated with oxybenzone. Not only that, but some studies have shown that it penetrates the skin and then increases the production of free radicals when exposed to light. You definitely don’t want a sunscreen ingredient that reacts to the sun by increasing free radical production. This is one way in which oxybenzone is considered a carcinogen. 
Using natural sunscreen is a no-brainer. Zinc oxide has long been one of the safest and most trusted sun protection ingredients. It’s a physical sunscreen, which means it blocks the rays from getting to your skin, rather than just neutralizing them.
Using sunscreens with zinc oxide can give you protection from the sun with a side of peace of mind that you are not contributing to the death of our coral reefs.