Aquaphilia also called hydrophilia is a term used to describe a form of sexual fetishism which involves images of people swimming or posing underwater, and sexual activity in or under water. Literally "water lover" from the Latin aqua and Greek φιλειν (philein).

http://en.wikipedia.org/wiki/Aquaphilia_Fetish

So guys in the shower, pools, bathtubs, playing with hoses, swimming in the ocean, anything and everything to do with wet guys, its a small niche that has a huge following

Regards,

Lee