Sea Battle
Sea Battle is a 15-minute game for 2: hide your fleet on a 10×10 grid and take turns firing at squares to sink your opponent's ships. Sink them all first to win. Free in your browser, no sign-up.
Play over time
Sea Battle in 30 seconds
- Set upHide five ships (carrier 5, battleship 4, cruiser 3, submarine 3, destroyer 2 squares) across or down your 10×10 waters.
- FireTake turns firing at one square in enemy waters. It is a hit if a ship is there, otherwise a miss.
- SinkWhen every square of a ship has been hit, that ship is sunk.
- WinSink the whole enemy fleet first.
At a glance
| Item | This game |
|---|---|
| Players | 2 players |
| Play time | About 15 min |
| Type | Board |
| Ranked play | No |
| Practice against the CPU | Yes |
| Price | Free (no account needed) |
| Rights holder | A public-domain classic game |
| Last updated | 2026-09-19 |
How to play Sea Battle online with friends
- Tap "Play with friends"A party is created with a 6-character code. No account is needed.
- Send a link or QR codeShare it on LINE, or just read the code aloud.
- Everyone opens it in a browserOnce 2 players have joined, the host taps "Start".
Rule highlights
Setup, play, winning, and house rules
Setup
- 2 players. On your own, play against the computer.
- Your waters are a 10×10 grid (rows A–J, columns 1–10). Place a carrier (5 squares), battleship (4), cruiser (3), submarine (3) and destroyer (2).
- Ships go straight across or down — never diagonally, and never overlapping. Ships may touch.
- Your fleet starts laid out for you. Tap a ship, then tap a square to move it; Rotate turns it and Shuffle lays the fleet out again. Tap Ready when you are done.
How to play
- Starting with the first player, take turns firing at one square in enemy waters.
- If a ship is there it is a hit, and you are told which ship. Otherwise it is a miss.
- When every square of a ship has been hit, that ship is sunk.
- Use your hits to work out which way a ship runs, and narrow down where the others can hide.
Winning
- The first to sink the whole enemy fleet wins.
House rules
| Name | Description | Default | Changeable |
|---|---|---|---|
| Fleet | Five ships (carrier, battleship, cruiser, submarine, destroyer) or ten ships (one of 4 squares, two of 3, three of 2, four of 1). | Five ships | Can be changed |
| SalvoSalvoA salvo is a volley of shots. Each turn you fire one shot for each of your ships still afloat, so losing ships means firing fewer shots. Whoever sinks ships first pulls further ahead, and games finish faster than one shot at a time. | Each turn, fire one shot for every ship you have left (five at the start). Pick the squares, then tap Fire. | Off (one shot a turn) | Can be changed |
| Fire again after a hit | After a hit you fire again, until you miss. Not used with Salvo. | Off | Can be changed |
| Ships may not touch | Ships cannot be placed next to each other, corners included. | Off (ships may touch) | Can be changed |
| Keep hit ships secret | A hit does not say which ship was hit; you only learn a ship's name when you sink it. | Off (every hit names the ship) | Can be changed |
| Swap first player on rematch | Play again switches who fires first. | On | Can be changed |
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FAQ
How many can play?
2 players. On your own, play against the computer.
What kind of game is it?
A two-player deduction game long played with pencil and paper. Find the ships hidden in your opponent's waters by firing at one square at a time.
Can we play on a call?
Yes. Every shot and its result is shown on screen, so you can talk tactics and banter while you play.
Can I play on a phone?
Yes. No app is needed — just open it in a browser. You can join the same party as people on a PC or tablet.
Can two people play?
Yes. This game supports 2 or more players.
Can we play without being online at the same time?
Yes. Choose “Turn-based (told each turn)” and you can make one move whenever you like. We tell you when it is your turn. A table ends automatically, with no winner or loser, after 45 days without a move.
Rights holder and physical edition
This is a public-domain classic game. The rules follow the standard reference rules.
Related games
Same type (Board)
Same player count
Last updated 2026-09-19 · Run by Qdan, Inc.