Saturday, 12 September 2026
Work out which squares are sea and paint them. There is only ever one way it can go, and you never have to guess.
0 squares flooded
- sea
- island, and only a note to yourself
Tap to flood a square, again to mark it island, again to clear it. Only the sea is scored, so the island marks are yours to use or ignore.
Stopping early still scores, on the sea you had right.
Today’s board
Time, best first · points1 person has played this today and nobody has solved it yet. Make an account and your name goes up here when you do. This board ranks solved runs, because it ranks them on the clock and a part-solved grid cannot be compared with a finished one. Every go earns points on the leaderboards either way.
This week, this month and all timeTideline
Work out which squares are sea and paint them. There is only ever one way it can go, and you never have to guess.
- Tap a square to paint it sea, again to mark it land, again to clear it.Only the sea is scored. Marking land is a note to yourself, so use it as freely as you like and leave it out where you do not need it.
- Start with the numbers. A 1 is an island on its own, so everything touching it is sea.A square with two different numbers beside it is sea as well, because joining them would make one island with two numbers on it, which is never allowed.
- Remember the sea can never fill a two-by-two block.So wherever three squares of a two-by-two are sea, the fourth has to be land. That one rule breaks open more grids than anything else here.
Scored on time.
What the words mean
- The sea:
- the painted squares. All of it has to join up into one stretch
- An island:
- a run of unpainted squares joined side to side, with exactly one number on it
- A pool:
- a two-by-two block of sea. Never allowed, anywhere on the grid
- Touching:
- sharing a side. Corners do not count, so two islands may sit diagonally
Had enough of today’s? Play Tideline unlimited, as many as you like.