What is Battleship Solitaire (Bimaru)?

Battleship Solitaire (also known as Bimaru, Yubotu, or Naval Solitaire) is a logic deduction puzzle invented by Jaime Poniachik. Players must discover the exact positions of a hidden armada of ships using row and column counts as clues.

Can ships touch each other in Battleship Solitaire?

No. Ships are strictly forbidden from touching each other, even diagonally. Every ship segment must be surrounded by water on all sides, except where it connects to another segment of the same ship.

What does a standard Battleship fleet consist of?

A standard 10x10 fleet contains 10 ships totaling 20 segments: 1 Battleship (4 squares), 2 Cruisers (3 squares), 3 Destroyers (2 squares), and 4 Submarines (1 square). Smaller grid sizes use proportional sub-fleets.

What do the numbers outside the grid mean?

The numbers outside each row and column indicate the exact total number of ship segments hidden in that specific row or column.

What is Battleship Solitaire (Bimaru)?

Battleship Solitaire (also known as Bimaru, Yubotu, or Naval Solitaire) is a logic deduction puzzle invented by Jaime Poniachik. Players must discover the exact positions of a hidden armada of ships using row and column counts as clues.

Can ships touch each other in Battleship Solitaire?

No. Ships are strictly forbidden from touching each other, even diagonally. Every ship segment must be surrounded by water on all sides, except where it connects to another segment of the same ship.

What does a standard Battleship fleet consist of?

A standard 10x10 fleet contains 10 ships totaling 20 segments: 1 Battleship (4 squares), 2 Cruisers (3 squares), 3 Destroyers (2 squares), and 4 Submarines (1 square). Smaller grid sizes use proportional sub-fleets.

What do the numbers outside the grid mean?

The numbers outside each row and column indicate the exact total number of ship segments hidden in that specific row or column.

Naval Logic Classic • Bimaru

Battleship Solitaire

Command the radar! Locate the hidden fleet using row and column segment tallies. Zero diagonal contact permitted!

Warmup • 6×6

⏱ 0:00

Cruiser: 0/1

Destroyer: 0/2

Submarine: 1/3

Calibrating naval sonar...

Battleship Solitaire (Bimaru) Rules

Published across the globe under titles like Bimaru, Yubotu, and Solitary Battleships, this game pits pure deduction against the open sea:

1. Line TalliesThe number beside each row and column specifies the exact count of ship segments residing in that line.

2. Strict Isolation (No Touch)No two ships may touch each other horizontally, vertically, or diagonally. Water must separate all ships.

3. Straight HullsShips are strictly straight rectangular segments of width 1. L-shaped or T-shaped ships are invalid.

4. Exact Fleet MatchThe board must contain the exact distribution of ship sizes specified in the fleet roster.

Radar Deduction Strategies

Sweep the Zeroes: Any row or column with a clue of “0” contains no ship segments. Immediately fill all cells in that line with water waves (`~`).
The Diagonal Water Rule: Because ships can never touch diagonally, whenever you identify a ship segment, all four diagonal neighbors must be water. Marking these immediately clears large swaths of the board.
Hunting the Battleship: Large ships (the 4-segment Battleship and 3-segment Cruisers) have very few places they can legally fit. Scan lines with small clues (≤ 2) — no large ship can lie parallel in those lines!
Submarine Isolation: A single submarine segment (length 1) must be surrounded by water in all 8 adjacent squares.

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