Water

Water is one of the substances that can't be placed by the player. On newly generated maps water is quite common at ocean level. It can also be found in pools underground and lakes above ground.

Water spreads horizontally and downwards by duplicating itself to empty squares. Water spreads very fast, about the speed of a walking player, and if left alone will cover everything at or below the level the water started at if there's a direction connection to it. Water is transparent, and will also slow down your character if it is moving through it. Water cannot spread within a five-by-five area of sponge (Two blocks on each side, with Sponge at its center).

You can remove water by building in the same area as the water occupies, and then remove the new build blocks. Remember to close the source before you start fixing your waterfilled room(s). With the addition of sponge however, flooded areas require much less work to 'unflood'.

Water's texture was changed in the 0.0.19a client update on June 20th, 2009, and is now animated.