The seamoth is a fast, safe mode of transport, but remember that swimming is good for your glutes and endorphin levels.


― PDA, Dialogue


The Seamoth is a small one-person submarine that can be constructed using the Mobile Vehicle Bay. It is a versatile Vehicle that can travel at high speeds underwater, and can be customized with a Vehicle Upgrade Console at a Moonpool.

Before the Seamoth can be constructed, the player must first scan three Seamoth Fragments using the Scanner. These can be found in Wrecks in the Grassy Plateaus and in the Aurora.


The player can enter the Seamoth with LMB, or XBOX Left Trigger/XBOX A. Once inside, the player can maneuver the Seamoth using the same controls as swimming, or press E or XBOX B to exit the Seamoth. The player can toggle the Seamoth's headlights on or off with RMB or XBOX Right Trigger.

The Seamoth requires Energy from a Power Cell in order to function. On one full charge, the Seamoth can travel approximately 10,650 meters (106.5m per percentage of energy) before running out of Energy. To recharge the Seamoth, the player can replace the Power Cell on its back or dock it at a Moonpool or Cyclops (draining energy from the Seabase or Cyclops to recharge the Seamoth's Power Cell).

The Seamoth generates its own Oxygen supply as long as it has Energy (this does not consume any of its Energy). When the player enters a Seamoth that has Energy, their oxygen is fully replenished. This enables the player to dive into deeper areas of the ocean that are not easily accessible by swimming or by using the Seaglide.

Compared to the Cyclops and the Prawn Suit, the Seamoth is significantly faster and more agile, making it excellent for exploration. However, it is more prone to damage, and even a fully upgraded Seamoth cannot go deep enough to explore the deepest biomes (such as the Inactive Lava Zone and Lava Lakes).

Upon entering the Seamoth, its AI says "Welcome Aboard Captain."


Titanium IngotPower CellGlassGlassLubricantLeadArrow-right (1)Mobile Vehicle BayArrow-right (1)Seamoth


The Seamoth has its own Health percentage which will decrease if it is attacked by hostile creatures, crashed into objects (including some plants) or crushed by pressure resulting from diving below its crush depth. The player can repair this damage with the Repair Tool. Once the Seamoth's health reaches 0%, it will explode.[1]

The acidic brine in the Lost River deals periodic damage to the Seamoth.

If the Seamoth is in an area with a temperature greater than 70°C, it will begin to gradually take damage.


The Seamoth produces enough forward thrust to travel at a maximum speed of about 12.7 m/s, and enough lateral thrust to travel at about 11.3 m/s.

When exited, the Seamoth will preserve its momentum and place the player behind it. The player should be careful not to exit the Seamoth while quickly moving with dangerous creatures around, as the Seamoth may move away from the player before the player can get back in, leaving them vulnerable to attack.

Upgrades and Customization

The Seamoth can be customized with the Vehicle Upgrade Console. The console allows the Seamoth to be named and its colours changed. The console also crafts upgrade modules for the Seamoth. Up to four of these modules can be applied to the upgrade panel found on the Seamoth's left wing.

Seamoth Depth Module MK1

Depth Module Compensator

The Seamoth has a crush depth of 200 meters. 20 Meters before the player reaches the crush depth a warning will appear letting the player know that it is approaching. Below 200 meters the on-board AI will state:

"WARNING: Maximum depth reached, hull damage imminent".

At that depth the Seamoth will take hull damage at a constant rate of about 7% per second. It is possible to increase the Seamoth's crush depth adding Depth Module upgrade. These upgrades do not stack and can be further upgraded by Modification Station.

Influence of Depth
Depth Module Crush Depth
None 200 meters
Seamoth Depth Module MK1 300 meters
Seamoth Depth Module MK2 500 meters
Seamoth Depth Module MK3 900 meters
Seamoth Storage Solution

Storage Module

The Storage Module upgrade provides a 4x4 storage compartment, which can be installed on each of the 4 slots on the Seamoth.

Seamoth Hull Reinforcement

Hull Reinforcement

Permanently hardened chassis before collision, eliminating damage under normal conditions.

Seamoth Power Efficiency Module

Engine Efficiency Module

The Engine Efficiency Module recycles heat by-product to minimize power inefficiencies. Each module reduces power use by 15%.

Seamoth Solar Charger

Seamoth Solar Charger

The Seamoth Solar Charger is an upgrade module that enables the player to recharge their Seamoth's battery while in the sun.

Seamoth Perimeter Defense System

Seamoth Perimeter Defense System

Generates a localized electric field designed to ward off aggressive fauna.

Seamoth Torpedo System

Torpedo System

A standard underwater payload delivery system adapted to fire torpedoes:

Seamoth Sonar

Seamoth Sonar

A dedicated system for detecting and displaying topographical data on the HUD

Data Bank Entry

Seamoth Data Bank Image

The seamoth is a one-person vehicle with an independent, replaceable power cell fitted in the rear and a fully customizable design. Low power, multi-directional thrusters enable it to function equally well in sea or space environments.

Most long-range vessels carry at least two vehicles of this class to facilitate the exploration and exploitation of small astronomical bodies, however they can also be fabricated at a standard mobile vehicle bay.


  • Top Speed: 13m/s
  • Acceleration: 5m/s/s
  • Distance per power cell: 10km
  • Crush depth: 200m below sea level
  • Upgrade module slots: 4
  • Dimensions: 3m x 1.5m x 1m
  • Persons: 1

Seamoths may be modified by installing upgrade modules to the access point mounted on the wing. These include:

  • Increased cargo storage
  • Superior power
  • Pressure and collision compensation
  • Enhanced sonar
  • Defensive capabilities

NB These modules may only be manufactured at a moonpool outfitted with a vehicle modification station.

'The Seamoth: It goes anywhere but land.'



For a more complete gallery, visit Seamoth/Gallery.


  • The old Seamoth Pressure Compensator (Depth Module) has the same crush depth of a Cyclops Ultra Hull Reinforcement Module. However, it is now unobtainable, having been replaced by the Depth Module, and cannot be upgraded. If a player has one, it is considered a separate item from the Pressure Compensator.
  • The Seamoth is also suitable for use in space.
  • The Seamoth's AI used to occasionally say "I love it when you come inside me" instead of "Welcome aboard, Captain." This was a joke slipped in by the sounds producer, Simon Chylinski. After discussing the line with the dev team, Simon removed it as a lot of minors and families play Subnautica.
  • The Seamoth Bay had a Data Bank Entry once


  1. Dated June 24, 2015.