Okay, so during the volleyball scene they probably were using sun tan lotion or oil, and sometimes the boys have just got done showering, but you could fill an Olympic swimming pool with all the sweat in this film. Stinger's bald head looks like he just dunked it in a tub when he's yelling at Maverick and Goose, the boys are always sweaty after their flights, and the guys in the air control tower on the aircraft carrier always have beads of sweat on their heads.
So what's with all the sweat? A few things.
First, flying a jet is an incredibly exhausting and athletic activity. Seriously. When you're flying a plane that can dive, go upside down, and pull more G's than you ever thought possible, you're definitely gonna sweat a little bit. We're guessing those cockpits don't have AC, and when throw in a bunch of heavy flight gear, a helmet, and an oxygen mask, you have a recipe for one wet ride.
So sweat equals exertion. What else? Well, sweat is sexy, sort of. It makes us think of passion, performance at the highest level (in the air and in other places). It's no secret that the cast of Top Gun is full of lot of good-looking dudes. Good looking guys sweating all the time and walking around with their shirts off—yeah, that was definitely Tony Scott and Co.'s bid for female viewership and their attempt to give the film a gritty and edgy sexiness.