Island Sea
An archipelago puzzle. Each number sits on an island exactly that many cells big. Everything else is sea — and the sea must join up without ever forming a 2×2 pool.
Decide land or sea for every cell: each number is an island of that size, and the sea joins up.
FreeOn this device
Solved on this device: 0 of 12. Each board has exactly one answer, checked by a solver.
This 1's island has 1 cell so far — complete.
Controls
- Tap a cell to cycle unknown, land and sea.
- With the keyboard, move with the arrow keys; L marks land, S marks sea, Backspace clears, Space or Enter cycles.
- Focus a number to outline its island so far and hear its size. Check, Hint, Apply hint, Undo and Reset are always available.
The rules
- Each island is a group of land cells joined side-on, holds exactly one number, and has exactly that many cells.
- Different islands may touch at corners but never side-on.
- All sea cells join into one body side-on, no 2×2 block is all sea, and every cell must be marked before the board counts as solved.
Scoring, saving and limits
Solved means every rule holds with every cell decided. A hint that reveals a cell marks the run as assisted.
Your marks, undo history and solved boards are kept on this device only. Download a backup to move them.
Twelve original boards (six 5×5, six 7×7), each checked by a solver to have exactly one answer. Hints use local reasons first and say so when they reveal a cell instead.
Questions
- Can two islands touch diagonally?
- Yes. Only side-on contact would merge them.
- Why must every cell be marked?
- An undecided cell could be either, so the board is not finished until each one is land or sea.
- Does a cell belong to the nearest number?
- Not necessarily — the island shapes come from the rules together, which is why the game never assumes it.