Sun Balm tested at SPF 50 and 2HRS water resistance and SPF 40 and 4HRS water resistance. We are extremely proud of that.
What this means is that testing after 2 hours in the water on 10 people the results came in above 50SPF. AND on a whole different set of people, after 4 hours in the water, the tests still came in at above 40SPF. We know the anhydrous formula and photostability of Sun Balm has a lot to do with those results.
For product maker, John, a surfer and white water kayaker, who is bald and fair-skinned, great water resistance was paramount. Coming out of the water after hours in the surf you can still feel the product on your skin, working hard. Surf is the ultimate test for water resistance.
This is a product designed for water sports.
While those numbers give you a lot of peace of mind, we still recommend wearing smart clothing, a hat, and re-applying every 2 hours, or when coming out of the water and after towel drying. This is skin respect.