Minecraft wiki entry for Water, associated text: The button for swimming is the same as the button for jumping; non-swimming players and mobs sink slowly in water. Holding the swim button raises the player through the water, and when the surface is reached, the player bobs up and down. The crouch button can be used to sink faster. The sprint button can be used to put the player in "swim mode" when the player is completely submerged in water. When in swim mode, the player is horizontal and one block high. The player has an arm-waving animation when viewed in third person or by other players.