[Field Scout]

Alot depends on length of exposure and spf rating, I used to do alot of South American surfing and I would use a product called Aloe Gator 40+ super waterproof sunblock gel (its the best stuff ever imo, apply 20 min prior to exposure and it really last all day. But it must be gel no lotion.) after surfing all day for 2 weeks I was tan but not dark.