Deep Sonar is a mine deduction puzzle at sea, built so you never have to guess. Each board opens with some water already revealed. Tap a covered cell to reveal it. A number counts the sea mines inside that cell's sonar shape; tap a number to light up its reach. A zero opens its surroundings for you. Flag a mine with a long press, a right-click or Flag mode. Clear every safe cell to finish.
The sonar shape changes as you go. A ring counts the eight touching cells. A cross counts two cells straight up, down, left and right, but no diagonals. A diagonal counts two cells along each diagonal. When shapes are mixed, a small symbol on each covered cell shows what it will measure. Later boards add yellow edge numbers that count the mines in each row and column.
Sixty boards run across five tiers, from Shallows to The Abyss, and there is a daily board. Hitting a mine is a mistake; undo and carry on. A clean solve earns three stars, and each mistake costs one. The hint points to the next safe deduction, explains it in words, and caps the board at two stars.
Worked example
On a ring board, a 1 with only one covered cell around it tells you that cell is a mine, so flag it. Next, compare two clues that overlap: if every covered cell of a 1 is also seen by a 2, the 2's second mine must sit in the cells the 1 cannot see.
Strategy tips
Read the shape before the number. A 2 on a cross means something quite different from a 2 on a ring.
Use the edge totals. When a row needs one mine and a clue already accounts for it, the rest of that row is clear.
Watch for red. A clue with more flags around it than its number turns red, a sign that a flag is wrong.