Shoals: Logic Charts

Chart the hidden rocks of a quiet bay. Sound a square of an old sea chart and it shows its depth – how many rocks touch it – then put a buoy on every rock you are sure of. Notes in the chart margins count the rocks in each row and column. 280 charts, each with exactly one solution you can reach by logic alone – never a guess.

Support

Found a bug, stuck on a purchase, or have an idea? Email [email protected] – please include your phone model and, for a puzzle question, the difficulty and level number.

Frequently asked questions

How do I play?

Tap a covered square to sound it. Open water shows a depth number: how many rocks touch that square. A 0 opens its neighbours for you. Long-press a square (or switch to Buoy mode) to put a buoy on a square you are sure hides a rock. Tap a number whose rocks are all buoyed to sound the rest of the squares around it – and the reverse works too.

What do the notes in the margins mean?

They count the rocks in that row or column. {3} means the three rocks sit side by side in one group; -3- means they are split into at least two groups.

What happens if I tap a rock?

It is not game over. The move is refused, nothing on the chart changes, and it counts as a mistake. You simply keep going.

I bought a pack but the levels are still locked.

Open any locked level to get to the Purchases page and tap Restore Purchases. Make sure you are signed in to the store with the same Google or Apple account you used to buy it.

I got a new phone. Is my progress saved?

Purchases are tied to your store account and can be restored on any device. Your progress and best times are stored only on the phone you played on and are not synced.

Do I ever need to guess?

No. Every chart has exactly one solution and can be solved by logic. If you are stuck, the Hint button first shows where to look, then explains why, and only then makes the move.

What do the free and paid levels include?

All 40 Easy levels (including a five-level tutorial) and the first 10 levels of Medium, Hard and Expert are free. The rest come in one-time packs of 35 levels, or all at once. There are no ads, no subscriptions and no account.

What data does the app collect?

Only anonymous gameplay statistics and crash reports, and you can switch them off in Options – see the privacy policy.