Sponge

Sponge is a utility block used to remove water in large areas quickly. When placed, a Sponge absorbs nearby water blocks—both flowing and source—within a 7-block taxicab radius (up to 135 blocks total). Upon doing so, it turns into a wet Sponge, which no longer absorbs water.

Wet sponges can be dried out in a furnace or instantly in the Nether, turning them back into regular sponges. In Bedrock Edition, they can also dry over time in dry biomes. Sponges are found only in ocean monuments, either as loot from elder guardians (always drop one) or within Sponge rooms that contain about 30 wet sponges on average.

They’re most effectively mined using hoes, and when used properly, can help clear out waterlogged areas for underwater builds, monuments, or farming setups.