Aquarium

Rules

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 janko.at)

Rule variations

• 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

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

• WPC 2019/Round 3 (Permaculture hybrid with LITS) by Silke Berendes
• WPC 2019/World Cup Playoffs by Rainer Biegler
• WPC 2018/Round 1 by Jiři Hrdina