Finding a reef friendly sunscreen has been a challenge. Either they aren't easy to apply and/or don't last very long. Tropic Sport has created a great product that is easy to apply, lasts more than a couple of hours and works extremely well. It is a premium product and costs accordingly, so, I would take one star away for that but I won't because it's really a great product. (hey, I'm a cheap actuary!). I do love this stuff and I will continue to buy and use it. It really works.