What is Battleship Sudoku?
Battleship Sudoku is two classic games rolled into one. You solve a normal 9×9 sudoku grid — every row, column and 3×3 box needs the digits 1 to 9. At the same time, a secret fleet of ships is hiding in the grid.
Already love classic 9×9 sudoku? You already know half the rules. Just add the fleet hunt on top.
The fleet is made up of 10 ships: one big Battleship (4 cells), two Cruisers (3 cells), three Destroyers (2 cells) and four submarines (1 cell). Ships can face left-right or up-down, and no two ships can touch — not even diagonally.
How the row and column counts work
Along the right edge of the board you'll see a number next to each row. That number tells you how many ship segments are hiding in that row. Along the bottom you'll see numbers for each column.
If row 3 says "2", exactly two cells in that row are ship segments. Use those counts alongside the sudoku clues to narrow down where ships can go.
How to mark ships
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Switch to Ship mode
Tap the ⚓ Ship button in the toolbar. The board switches to ship-marking mode.
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Tap cells to mark ships
Tap any cell to toggle it as a ship segment. An anchor ⚓ appears to remind you.
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Confirm a ship automatically
When all cells of a ship are correctly marked AND you've filled in the right sudoku digits, the ship glows and shows its digits in the fleet panel.
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Switch back to digits
Tap the ⚓ Ship button again to switch back and keep solving the sudoku.
The fleet
- 🟦 1× Battleship — 4 cells in a row or column
- 🟪 2× Cruiser — 3 cells in a row or column
- 🟩 3× Destroyer — 2 cells in a row or column
- 🟡 4× Submarine — 1 cell (solo!)
The fleet panel on the side shows all 10 ships. Ships you haven't found show question marks (?). Once you correctly mark all cells of a ship AND fill in the right numbers, it lights up and shows the actual digits — your proof you found it!
Easy strategies
- 🔢 Zero rows/columns first — if the count is 0, no ships there
- 📦 Count of 9 — the entire row or column is full of ships
- ⚓ On Easy, some ships are pre-revealed — use them to figure out neighbours
- ✏️ Use Notes to pencil in sudoku possibilities, then check counts
- 🔎 Tap Check to see if any sudoku digit is wrong
Why kids love Battleship Sudoku
- 🧠 Trains two kinds of thinking at once: number logic AND deduction
- 🎨 Colourful fleet panel fills up as you find ships — instant satisfaction
- 🕵️ Feels like a detective mission AND a number puzzle
- ⏱️ Easy levels are quick; Expert levels are a real brain workout
- 📱 Works on phones, tablets, laptops and Chromebooks
Ready for more?
Once Easy feels comfortable, try Medium Battleship Sudoku. From there you can graduate to Hard Battleship Sudoku and finally take on Expert Battleship Sudoku — fewer starting digits, no pre-revealed ships, every deduction counts.
Want a break from ships? Switch to classic 9×9 sudoku for pure number logic, or try our starter 4×4 sudoku grid.
よくある質問
What age is Battleship Sudoku good for?
Most kids enjoy Battleship Sudoku from about 8 years old, once they're comfortable with basic sudoku. Younger children should try our regular sudoku or the 4×4 grid first.
Do I have to solve the sudoku AND find the ships?
Yes — you need both to win. The sudoku solution and ship positions are linked, so solving one always helps with the other.
What do the numbers on the edge mean?
The number next to each row tells you how many ship segments are in that row. The number below each column tells you how many ship segments are in that column.
Can ships overlap in the sudoku grid?
No — ships are separate and cannot touch each other, even diagonally. Each cell belongs to at most one ship.
Does it save my progress?
Yes — your sudoku digits, notes, ship markings and timer all save automatically in your browser. Close the tab and come back later.
Can I play without making an account?
Yes! Every puzzle on this site is free with no signup, no email and no ads in the way.
ほかの数独もあそぼう
ルールはちがっても、おなじやさしい盤面。つぎは仲間のパズルをえらんでね。