From WPC unofficial wiki


Aquarium Example.png Aquarium Example Solution.png

Fill some cells with water so that the numbers at the borders indicate how many cells in the corresponding row or column contain water. Within an area, the cells must be filled up from the bottom up. Within a row of an area, all cells must always be filled with water or none (even if there are other areas in between).

(Rules from WPC 2018 IB, example from

Rule variations[edit]

  • Rules on row of an area in between which other areas are present varies on occasions. For example,Puzzle Picnic adopts slightly different rules.

History of the puzzle[edit]

Invented by Naoki Inaba (Japan) in 2004. Originally named アクアプレース ("Aqua Place"). Original set of puzzles created by Naoki can be seen here.

Appearances in the past WPCs[edit]