Drain

Drain is an item that destroys any liquid around it. Unlike Pumps (which store the liquid for future use), the Drain will discard the liquid completely.

It can be used to clean your base after accidental flooding, etc.

Biome oceans (on planets like Aether Sea, Tidewater, etc.) are limitless and can never be drained. When under the ocean level, Drain would only be effective in an enclosed area with background blocks.