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 turns the picture into a 4 × 4 slide puzzle: 15 tiles and one empty space. The shuffle is fixed, so everyone starts from the same board, and it is always solvable.
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.
- Finish the top row first, then the left column; the puzzle shrinks to a smaller board each time.
- Switch on the numbers if two tiles look alike — they show where each tile belongs.
- Look-alike tiles are where the numbers help most: plain water or sand gives few clues about order.
- For the last two rows, work column by column, two tiles at a time.
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.
Wall dives drop off into bigger boards, where the plain parts of a picture start to slow you down.