Docks are platforms which stick out from land into a body of water.
The Legend of Zelda
The Wind Waker
In The Wind Waker, one dock can be found on Outset Island and another one on Windfall Island. The King of Red Lions will always relocate to the docks when Link returns to the Great Sea from another area.
In Phantom Hourglass, docks serve as the only access points to every island in the game. Steering the SS Linebeck into an island's dock while traversing the World of the Ocean King allows Link to visit the island.