Subnautica Wiki
This article is about Lava Geyser in Subnautica. For the related article on the Below Zero Wiki, see Lava Geysers.

Lava Geysers are areas of the ocean floor that spew out lava and steam. Some of these craters are located deep in caves and others may be found in the open ocean. These geological structures are classed as miniature biomes.

Every few seconds, the craters erupt, throwing steam and chunks of lava into the water surrounding it. They can only be observed from a safe distance, as their eruptions will cause massive damage to the Player. Even approaching the area near the geyser hurts the player due to the extreme amount of heat. However, the Prawn Suit can be used to protect the player from dangerous temperatures, enabling them to explore and collect resources near the Lava Geysers such as harvesting nodes or cooked edible fish.

It is sometimes a good idea to risk a short trip to the higher parts of a geyser located in the Safe Shallows, even at the beginning of a playthrough. It is greatly rewarding, yielding both Limestone and Sandstone Outcrops in good quantities. One can even find geysers quite close to spawn, less than 600 meters away.

The temperature of the geysers makes them a great place to use the Thermal Plant to produce energy and then transmit it via a Power Transmitter.

Seabases will not protect the player from eruption damage. Any wandering fish in the area that dies of the eruptions or that come into contact with the lava will turn into their respective cooked forms, assuming that they have one.

Lava Geysers can be found in the Safe Shallows, the Bulb Zone, and one of its caves, the Jellyshroom Cave, and under the Underwater Islands.

Thermal Vents[]

Thermal vents, commonly known as "black/white smokers", are similar to lava geysers in their heat emission, though they do not erupt and are generally found in much deeper biomes such as the Deep Grand Reef and the Lost River. Thermal vents appear as dark-colored chimney formations of the sea floor that spew out a distinct cloud of black particles.



  • The hole for the large geyser in the Safe Shallows was originally designed to be a giant coral structure. According to a Subnautica level designer in his YouTube playlist, the Safe Shallows already had too much content to it, so it was instead modeled to be a sort of mysterious pit based off of the "Sarlacc Pit". The pit was left empty until the geyser was added.
  • If the player has a propulsion cannon they can hold small fish up to the geyser to cook them. Alternatively the player can go inside a Prawn Suit and grab the fish that were unfortunate enough to swim too far down the geyser.