In the frame
Two yellow and white butterflyfish with fine dark lines swim in front of a big red sea fan. Black and yellow feather stars cling to the reef below, and the left side of the picture is open deep blue water.
This dive cuts the picture into 15 square tiles on a 5 × 3 board and shuffles them. Swap two tiles at a time until the picture is whole; tiles that reach their home spot lock.
Dive plan
- Start with the easy part: the red sea fan and the two yellow fish.
- Save for last: the open blue water. About 33% of the frame has little detail, mostly on the left side, and those pieces look alike.
- Swap each tile straight to its home spot; it locks there, and the tile you displaced is the next one to place.
- If every swap sends a tile home, 14 swaps or fewer finish all 15 tiles.
- Place tiles with an outline, a fin or an edge first; the plain ones are easier once only a few spots remain.
- Fix the corners first: they are the easiest tiles to place by eye.
Colours of the picture
Main colours, measured from the picture's pixels: brown (47%), ocean blue (30%), charcoal (11%) and deep blue (8%).
- brown47%
- ocean blue30%
- charcoal11%
- deep blue8%
- grey3%
How deep it goes
Depth 3 of 5 — a steady dive.
Reef dives sit in the middle: enough pieces to need a plan, never so many that a phone screen feels crowded.