Hide a fleet of five ships on a 10 by 10 grid and hunt the computer's fleet, one shot per turn. Three levels, a daily fleet and no sign-up.
Sea Battle is a two-player ship hunting game on a 10 by 10 grid, and here you play it against the computer: you win by sinking all five of its ships before it sinks yours. Each side hides a fleet of five ships that take up 5, 4, 3, 3 and 2 squares in a straight line, across or down, for 17 squares in all. They are the Carrier, Cruiser, Frigate, Submarine and Patrol boat. Squares are named like D4: the column letter from A to J, then the row number from 1 to 10. You fire first and the shots then alternate, one shot per turn. A hit gives no extra shot, so the turn passes either way. The page tells you if a shot was a miss, a hit, or a hit that sank a ship and then names the ship. A ship is sunk when every one of its squares has been hit. The game ends the moment the last ship goes down.
Tap a ship in the list, then tap the board to put its first square there. The ship points right, or down after you press Rotate (the R key does the same). If it would hang over an edge, it slides back inside: with the Carrier pointing right, tapping I1 puts it on F1 to J1. Tap a ship that is already placed to pick it up and move it. Random placement lays out all five at once, and Clear starts again. The No touching ships option is on by default. With it on, no two ships share an edge or a corner, so every ship is surrounded by water, and the page says so when a spot is refused. Turn it off to allow ships side by side. The setting applies to the computer's fleet too. The Daily option gives the computer the same fleet for everyone who plays that date with the same no-touching setting.
The computer only uses what you could see: its own hits and misses, and which of your ships it has already sunk. Easy fires at a random square it has not tried. Medium hunts on a checkerboard pattern, because every ship of 2 or more squares must cover one of those squares, and after a hit it fires at the squares next to it and then along the line of hits. Hard counts, for every square, how many ways the ships still afloat could fit without breaking what the shots have shown, gives extra weight to placements that cover an unsunk hit, and fires at the square with the highest count. With No touching on, Hard also knows that the squares around a sunk ship are empty. None of the levels sees your ships, and the computer's fleet is placed before the game starts, so it cannot move. In the tests Hard needs fewer shots on average than Medium, and Medium fewer than Easy, over 40 seeded fleets.
A good opening is to fire on every other square in a checkerboard pattern, then work around any hit. After a hit, try the four squares next to it; two hits in a row show the direction, so keep going along the line until the ship sinks. With a keyboard, the arrow keys move around the board, Enter or Space places a ship or fires, and R rotates in placement. On a phone the computer's waters are the large board and your fleet is the small one in the corner: tap the small board, or Show my fleet, to swap them. A screen reader announces each square, its state and every shot. The game in progress, your settings and your record against the computer are saved in this browser. There is no sound, no clock and no online play.
Five ships on a 10 by 10 grid: a Carrier of 5 squares, a Cruiser of 4, a Frigate of 3, a Submarine of 3 and a Patrol boat of 2. That is 17 ship squares out of 100.
No. Each side fires one shot per turn, you first, and a hit gives no extra shot. The turn passes whether the shot is a hit or a miss.
With it on, no two ships may share an edge or a corner, so each ship is ringed by water. It applies to your fleet and to the computer's. Turn it off if you want ships side by side.
Select a ship in the list, press Rotate to switch between pointing right and pointing down, then tap the board. A ship that is already placed can be picked up by tapping it.
It counts every way the ships still afloat could fit on the squares it has not ruled out, favours the ones that cover a hit it has not finished, and fires at the busiest square. It does not see your ships.
A computer fleet picked from today's date on your device, for example 2026-10-15, so everyone with the same no-touching setting faces the same hidden ships that day. Only the first daily game each day counts for your daily streak.
No. The game is processed in your browser and not uploaded. The game in progress, your settings (level, no-touching and fleet choice) and your win record are saved in this browser's storage only. The page counts visits with Google Analytics, never your shots.