The game is played from the first-person and third-person perspective and can be played either in the single-player or multiplayer mode. With the latter, the server is automatically provided by the game and the game takes place in co-op mode.

After a world is created, the player starts on a 2x2 raft in the middle of an ocean. The player starts only with a hook that they can aim and throw to catch barrels, wood, palm fronds, plastic, crates, and other objects out of the water. The player can leave the raft and collect things while swimming, but must be careful as the raft is always moving due to the continuous ocean current. The player can also be attacked or killed by sharks that are always swimming around the raft. These sharks will also occasionally attack corners of the raft, destroying parts of it. Using a crafting system, the player can use the collected materials to assemble and research new items and to expand and improve the raft. For example, tools, weapons and nets can be manufactured, and a steering wheel can be made. These can be used to control and guide the raft, increase the size and stability of the raft, and defend the raft from the sharks.

The player also needs to manage basic needs like hunger and thirst by catching or growing food and purifying water to drink. When growing food, however, the player must protect the food from seagulls. One can do so by killing or driving away the seagull. During the game, the raft may pass by islands that the player can explore to get special items and resources. The player can also dive in coastal regions and collect special items.