Underwater Islands

Erosion patterns on the landmasses suspended here suggest they once floated on the surface. ― PDA, Dialogue

The Underwater Islands are a unique biome in Subnautica, featuring multiple and massive rock formations suspended above the ocean floor. Bonesharks dwell abundantly here, along with other types of fauna and flora. It also features its own cave system, the Underwater Islands Caves.

Description

Most of the Underwater Islands rely completely on the buoyancy provided by Ancient Floaters. Currently, there are eighteen islands in the area, with the size of the many "islands" varying from minuscule to massive. Two of the largest islands have a great variety of life forms and even possess their own separate cave system. A large ring of broken-off rocks surrounds the largest island; it is unknown how these rocks float without any attached floaters.

Hydrothermal vents can be found on the surface of the largest island, while Lava Geysers can be found in huge numbers on the ocean floor directly underneath the islands. Occasionally, large chunks of rock can be seen falling down from the islands and disintegrating. In some places, small streams of sand can be seen flowing down from over the edges of the islands.

Quartz is a common find on both the tops and walls of the islands, with Diamonds occasionally as well. Sandstone Outcrops and Shale Outcrops are located on the ground of most of the islands. Large Resource Deposits of Uraninite and Silver are located at the bottom with the Lava Geysers. Large Gold Deposits are rarely found near the cliffs around the biome, alongside Limestone Outcrops and Spadefish.

The Underwater Islands border one of the Mushroom Forests, Mountains, one of the Kelp Forests, the Northern Blood Kelp Zone, and one of the Grassy Plateaus.

Wreck 4 is located in the Underwater Islands, suspended by two of the islands.

The abundance of Boneshark pose an active threat to Seamoths and Prawn Suits. Consequently, maintaining vehicle wellbeing is important in the Underwater Islands.

Story Spoiler

An Alien Vent Entrance Point is found in the Underwater Islands.

Data

Key Coordinates

• General Coordinates: -40 -174 746
• Large Wrecks: -102 -179 860
• Thermal Vent Cluster: -110 -225 1000
• Lava Geysers: Various coordinates between -30 to -175 X, -495 to -520 Y, and 930 to 1100 Z.
• Alien Vent Entrance Point: -465 -70 870

Resources

All Data Boxes are found in Wrecks:

• Alien Containment
• Creature Decoy
• Cyclops Fire Suppression System
• Repulsion Cannon
• Swim Charge Fins

Raw Resources found in the biome or wrecks include:

• Copper Ore
• Coral Tube Sample
• Diamond
• Large Gold Deposit
• Large Silver Deposit
• Large Uraninite Deposit
• Lead
• Lithium
• Quartz
• Salt Deposit
• Silver Ore
• Titanium

Flora and Fauna

Fauna

• Ancient Floater
• Boneshark
• Boomerang
• Garryfish
• Hoopfish
• Peeper
• Reefback Leviathan
• Shoal of Fish
• Spadefish

Flora

• Redwort
• Violet Beau
• Drooping Stingers
• Earthen Coral Tubes
• Coral Shell Plate
• Purple Pinecone

Fragments

The following fragments can be found in Wrecks within this biome:

• Propulsion Cannon
• Stasis Rifle
• Cyclops Engine Fragment
• Power Cell Charger Fragment
• Prawn Suit Claw Arm Fragment
• Prawn Suit Fragment
• Prawn Suit Drill Arm Fragment
• Prawn Suit Grappling Arm Fragment
• Prawn Suit Propulsion Cannon Fragment
• Propulsion Cannon Fragment
• Stasis Rifle Fragment

Scannables

All Scannables are found in Wrecks:

• Bench
• Chic Plant Pot
• Command Chair
• Composite Plane Pot
• Desk
• Floodlight
• Office Chair
• Picture Frame
• Swivel Chair

Gallery

Overview

A view of one of the smaller islands of the biome

The largest Underwater Island

Ditto, viewed from underneath

Lava Geyser beneath the Underwater Islands

A view of the wreck in the biome

A closer view of the wrecks in the Underwater Islands

An Ancient Floater

Some Violet Beau in the area

The Underwater Islands

One of the longer Islands

One of the smaller Underwater Islands

Some floating boulders

A variety of life forms populating each of the Underwater Islands

Some Redwort in the Underwater Islands

The Wreck

Debris from the Wreck

The Underwater Islands caves

A small cave on the outskirts of the biome, housing Drooping Stingers

Thermal vents on the largest Underwater Island

The largest Island is anchored to the seabed near Lava Geysers, explaining its thermal vents

Transition with the nearby Kelp Forest

Transition with the nearby Grassy Plateaus

Transition with the Northwestern Mushroom Forest

Transition with the Northern Blood Kelp Zone

Transition with the Mountains

Trivia

• The PDA suggests that the Underwater Islands once floated on the surface, like the Floating Island.
• The old Biome ID for the Underwater Islands was "waterislands".
• The largest of the Islands is anchored to the seabed near the lava geysers, and has a long corridor in the middle of its cave; this probably explains the reason as to why there are thermal vents on top of it.