Let me first say that I'm a red head and no topical sunscreen has ever worked well for me if at all. That being said, I now live in Florida full time and have also spent time in Costa Rica with some intense sun as well. I've found a solution that works better than anything else guaranteed and haven't worn sunscreen for over ten years and haven't been burnt once as long as I fresh home made carrot juice.
I've got a spinal injury from a parachute accident with broken screws in my back. I've got to drink fresh home made juice every day or my back gets so bad I can't get out of bed. Usually I make carrot, celery, green apple which tastes amazing and gives you more energy than I ever thought was possible with no crash. It takes about 2-5 pounds of carrots juiced each day for this to work and it takes a week or so to start taking effect. I figured this out when I went to Costa Rica and was on the beach during high noon with no shirt and I didn't get burnt while others wearing sunscreen did. This blew me away because I was always the first to get burnt and could usually feel my skin starting to burn within 5 min normally. I knew something was different so I started researching and found that the betacarotene helps protect from the sun. I've found a couple articles that say to eat tomatoes or other things with betacarotene for protection as well. Let me say that it won't make a difference. I'm a raw vegan that buys tomatoes by the case. One winter I ate 1,300 points of tomato from my local organic farm and it didn't make any difference for sun protection. The only thing that works is juice and carrots specifically.
Most people first think about turning orange from the carrots but I've had none of that. The reason people turn orange is because the betacarotene is leaching out the toxins through your skin which shows up as being orange. Once your body adjusts it will return the a proper skin color with maybe just a slightly more tan look.
Now I tend to tan more or maybe for me it's mostly freckles but I don't get burnt. That being said I still take precautions and where a steamer suit or long sleeves to give me adde protection. Even if you don't get burnt the sun can do some serious damage and make you look much older than you really are. A close friend of mine used to sit out in the sun every day and now he looks jacked up compared to how he should be at his age. So the first step would be to get a steamer suit which I know ScubaPro has and also drink plenty of carrot juice each day.
there was one time I stopped drinking carrot juice and I got severely burned in half the amount of sun I was normally in with juice. The first thing I did was drink a half gallon of carrot juice and put some aloe on. That night I went to sleep with no pain in a hot room and no fan. Normally I would need a fan directly on the burn and sleeping would be miserable. There was also no peeling afterwards either and I retained more of a tan instead. Of course I kept drinking juice everyday after as well to help.
Most sunscreen actually has carcinogenic ingredients which is ironic because that's one thing most people are trying to protect themselves from.