Ocean Sudoku
An ocean puzzle game online, free: a picture sudoku with sea creatures in place of numbers, and every row, column and box needs each of them once. A 4x4 sudoku on easy, a 9x9 sea on medium and hard, a new board each time you press a level, with notes and a hint for when the tide turns against you.
How to solve ocean sudoku
The only fish left
For one empty square, cross out each creature its row, column and box already hold, the crab, the seahorse, the octopus. If one is left, it goes in.
Where can the whale go
Follow one creature, the whale, through one row. Any square whose column or box already has a whale is out. One square left: the whale goes there.
Out of your depth? Hint points to the next square and says which creature goes there and why.
The pictures
Twenty-four pictures from the sea, drawn for this game: fish and whales, crabs and shells, a seagull above and a nautilus below. Creatures that look alike when small, like the whale, the dolphin and the shark, never share a board, and each one keeps its own outline as well as its colour.
- Fish
- Whale
- Octopus
- Penguin
- Sea turtle
- Crab
- Jellyfish
- Seahorse
- Starfish
- Dolphin
- Shark
- Stingray
- Seal
- Seagull
- Walrus
- Pufferfish
- Squid
- Lobster
- Shrimp
- Seashell
- Coral
- Sea anemone
- Nautilus
- Seaweed
Questions
What is ocean sudoku?
A sudoku with sea creatures in place of numbers. Every row, column and box holds each creature once: four on the 4 × 4 board, nine on the 9 × 9.
Is it harder than a number sudoku?
No harder and no easier: the rule is the same, and a starfish does the job of a 5. Medium and hard are full 9 × 9 sudokus.
Why do the whale, the dolphin and the shark never meet?
All three are long grey-blue swimmers, and at the size of a square they blur together; so do the crab and the lobster. The game keeps them on separate boards, so every creature you see is easy to name.
Is there only one way to fill the sea?
Yes. The board is made when you press a level, and the game keeps it only if the creatures fit one way.
What if I get stuck?
Press Hint. It shows the next square and the creature that belongs in it, and points first to any creature in the wrong place.
Are there more picture sudokus?
Yes, eighteen more with the same rules. Near this one: Animal Sudoku, Bird Sudoku and Vehicle Sudoku, which has a ship and a submarine; each set keeps its own best times.
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