Valkur is the god of sailors and the sea in the Forgotten Realms. Valkur is often invoked to defend against Umberlee, goddess of sea and storm. Most sailors still provide offerings to Umberlee however, but Valkur is more the god of sailing as a profession than of the sea in the elemental sense.
In the 2.0 books, the Red Knight is trying to get him interested into taking up sea battles into his portfolio as well. As far as I know he hasn't, yet.