The Coral Nubbin is a craftable Item introduced in the Shipwrecked DLC. It is found in the Refine Tab, requires a Science Machine to prototype, and 3 Limestones and a Coral Larva to craft. The Coral Nubbin will spoil after 20 days once crafted, but can be placed in an Ice Box to slow spoilage. It allows the player to plant a new Coral Reef at a chosen location in Shallow Ocean. Once planted, the Reef will first be in an empty state, but will slowly grow Corals over time. After 12 Days, a Coral Reef is fully regrown.
- As the Coral Nubbin spoils, but the Coral Larva does not, it may be better to refrain from crafting the Coral Nubbin until the player is ready to place it.
- Coral Nubbins were added to the Shipwrecked DLC more than a year after its official completion in the Home Sea Home update, after being tested in a beta branch for several months.