This article is about the Survival Knife. You may be looking for the Thermoblade.
This article is about the Survival Knife in Subnautica. To see this subject's article on the Below Zero Wiki, click here.


Weapons were removed from standard survival blueprints following the massacre on Obraxis Prime. The knife remains the only exception.


― PDA, Dialogue


The Survival Knife is a basic tool crafted by using the Fabricator.


The Survival Knife's main function is to procure samples of certain Flora and corals, such as Creepvine Samples and Coral Samples. It can also be used as a weapon, but its damage and range are limited, and there is no real benefit to killing fauna in the first place.

By using the Modification Station, the Survival Knife can be upgraded to the Thermoblade.

If a Bleeder latches onto the player's arm, the player can use the Survival Knife to hit the Bleeder.


Silicone RubberTitaniumArrow-right (1)FabricatorArrow-right (1)Survival Knife


Survival KnifeBatteryArrow-right (1)Modification StationArrow-right (1)Thermoblade



  • Obraxis Prime is a reference to one of Subnautica's developers, Scott MacDonald, who goes by the alias of Obraxis.
  • Markings on the Survival Knife indicate that it was made by "Alterra Arms Incorporated". Alterra is a corporation also known from the game Natural Selection 2, which was developed by Unknown Worlds Entertainment, the developers of Subnautica.
  • One upgrade that was intended for the Survival Knife included adding poison damage to the knife
  • There was originally a second upgrade for the Survival Knife, called the Hardened Blade, but it was removed when durability was removed.
  • Survival Knife animations that were never implemented can be viewed here.
  • The Survival Knife originally had durability, but it was removed due to it being deemed useless.
  • The Survival Knife is capable of killing a Lava Lizard in ten slashes, whilst the Thermoblade is incapable of dealing damage to them.