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

The Thermoblade is a tool and an upgrade to the Survival Knife. It is crafted by using the Modification Station.

In general, it can be used for harvesting or defense. Its primary function is that it cooks any edible fish in one swipe.

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

Lava Lizards and Sea Dragon Leviathans are completely immune to the Thermoblade, presumably due to their own skin being adapted to extreme temperatures far surpassing the tool.


Survival Knife.pngBattery.pngArrow-right (1).pngModification Station.pngArrow-right (1).pngThermoblade.png



  • Markings on the Thermoblade indicate that it was made by "Alterra Arms Incorporated".
  • Despite being fabricated with a battery, the Thermoblade does not lose battery power ingame.
  • The boiling water effect is tied to the Thermoblade itself rather than the environment it is in. As a result, even when the player is in a Seabase , the blade will still appear to be surrounded by boiling water. However, above surface level, the blade will merely steam.
  • The Thermoblade once had durability, but it was removed due to durability being deemed useless.
    • When the Thermoblade did have durability, it had the lowest durability out of all the knives.