The shell field is now a focused set of 40 shells, all in the Kelp Forest between 640 m and 3,000 m. Each shell has several seeded resting spots, so the map feels alive without moving the find into an invalid depth or another biome.
The guarantees matter as much as the movement. A shell you have never prised never moves. A shell mid-countdown never moves — it settles only at the instant it reopens. Closing the game, reloading, or switching devices reshuffles nothing: a save comes back showing exactly the layout you last saw. And every candidate spot was proved safe before it shipped — no possible layout can bury a pickup, block a passage, or land a shell on top of anything that matters. Full mechanics in the guide: Pearl Shells.