You are shipwrecked on a mysterious and deserted volcanic island. In the wake of a storm, you come across a grounded and abandoned submarine: The Nautilus. You must explore it from top to bottom and collect as many objects as possible to ensure your survival, repair the submarine, and leave the island before the other castaways.

During their turn, players move their Castaway marker in a column and then choose between collecting object cards from the column or placing down cards from their hand to start a collection. Storing objects allows players to claim bonus and/or porthole tokens before their opponents and get victory points.

When a column is empty, the game ends. The player with the most victory points wins the game.