What is it with Leonardo DiCaprio and water?

Three out of the four Leonardo DiCaprio movies I've seen have connected him to the ocean and had him soaking wet. Titanic, Shutter Island, Inception... what other movies does Leo get drenched in? WHY?? Is it some kind of contract thing? Like only a few actors agree to go topless, and only a few actors agree to immerse themselves in water? Or is there some reason everyone wants to get Leonardo DiCaprio wet?