The Solid Foundation is used to expand the Raft, and is only visually different from the basic Foundation. It can be built with a Building Hammer. Solid Foundations can be destroyed with an Axe, or by the Shark. Placing Foundation Armor on a foundation block will prevent the Shark from attacking the Foundation.
- Expanding the Raft.
- If the last remaining foundation is destroyed, the game is essentially over, as the player cannot place any new Foundations.