The Seatruck is Subnautica: Below Zero’s signature vehicle — a modular submarine that can be customised with different function modules to serve as a transport, a mobile workshop, or even a home away from home. Unlike the Seamoth from the original Subnautica (which is compact and fast but offers no interior space) or the Cyclops (which is enormous and slow), the Seatruck strikes a balance: it has a small interior, can dock modules for additional functionality, and is manoeuvrable enough for exploration without being painfully slow. This guide covers everything you need to know about the Seatruck.
Building Your First Seatruck
The Seatruck blueprint is obtained from fragments in the early exploration areas — similar to the Seamoth in the original Subnautica. Finding and scanning the fragments is a high priority in the first hours of play. Once you have the blueprint, the Seatruck requires Enameled Glass, Lead, Titanium Ingots, and Lubricant — reasonably accessible early-game materials. Build it in a Moonpool.
The base Seatruck without any modules is small — just the cab unit. You sit in the front, can look out, and operate the vehicle. It has its own oxygen supply, providing air for as long as the vehicle is powered. Without modules, it functions as a fast personal submarine for solo exploration and resource transport.
Seatruck Modules and What They Do
| Module | Function | When to Build |
|---|---|---|
| Aquarium Module | Houses live fish for food supply, Bioreactor fuel | When you need a mobile food source |
| Docking Module | Allows a Prawn Suit to dock to the Seatruck | Before entering Prawn-required areas |
| Fabricator Module | Includes a Fabricator for mid-mission crafting | Mid-game for extended exploration |
| Sleeper Module | Contains a bed for time skip and health recovery | For long exploration missions |
| Storage Module | Large cargo space, 4×4 grid | Whenever you need to haul more than the cab holds |
| Teleportation Module | Late-game module for quick traversal | End-game locations |
Seatruck Upgrades
Beyond modules, the Seatruck itself can be upgraded at the Vehicle Upgrade Console in a Moonpool. The most important upgrades are: Depth Module (extends maximum operating depth, essential for reaching later story locations), Hull Reinforcement (increases integrity against creature attacks), Engine Efficiency (reduces power consumption, extending range), and Perimeter Defence (electric deterrent that damages attacking creatures and breaks Chelicerate grabs).
Seatruck vs Prawn Suit: Knowing When to Switch
The Seatruck handles ocean travel. The Prawn Suit handles deep terrain that requires precise mobility — underwater cliff faces, cave systems too narrow for a full sub, and areas with significant creature threat at close range. The Prawn Suit’s grappling arm and drill arm make it invaluable for specific tasks. The Docking Module allows you to bring both on a single mission, switching between them as needed. This combination is the standard end-game exploration setup in Below Zero.
Seatruck Tips and Tricks
- The Seatruck auto-navigates in a straight line when you hold the throttle and release the wheel — useful for planning a route while looking at your map
- Modules add drag and reduce speed — remove modules you do not need for specific missions
- The Seatruck can enter very tight spaces compared to the original Cyclops — take advantage of this in cave systems
- Recharge your Seatruck power cells at your base before long exploration missions — running out of power leaves you in complete darkness
- The sonar module helps with navigation in dark or murky deep ocean areas
Seatruck Coverage on RicardoPlays
Ricardo’s Below Zero series on the RicardoPlays channel covers the full Seatruck progression — from the first build to the fully-modded end-game configuration. The channel includes module setup guides and a breakdown of which upgrade order is most efficient for story progression. Watch the Seatruck-focused episodes for a visual guide to the vehicle’s full potential.
🌊 Watch on YouTube
Seatruck Fragment Locations
The Seatruck blueprint is assembled from fragments scattered in the early exploration areas. Unlike the original Subnautica’s Seamoth (which requires fragments from specific wreck sites), Below Zero’s Seatruck fragments are distributed more broadly in the Shallow Twisty Bridges, Kelp Forest, and early wreck sites near Delta Station. Scan fragments as you explore the early biomes and you will have the Seatruck blueprint unlocked within the first few hours of play without needing to search specifically for it.
If you are struggling to find the final fragments, deploy a Scanner Room near the search area and use Camera Drones to sweep the biome — all nearby fragments will be highlighted in your HUD, making the search dramatically faster.
Seatruck Power: Managing Your Energy Supply
The Seatruck runs on internal power cells, similar to the Seamoth in the original Subnautica. Understanding Seatruck power management is critical for extended missions:
- The Seatruck consumes power continuously while moving, accelerating faster in demanding conditions or with many modules attached
- Each module adds drag and increases power consumption — remove modules you are not using on specific missions to extend range
- Power cells can be swapped when depleted — carry spare power cells for long missions
- Docking in a Moonpool at your base fully recharges the Seatruck automatically
- The Seatruck’s engine efficiency upgrade reduces power consumption significantly — this is one of the most practical upgrades for extended exploration sessions
For a complete power management strategy, cross-reference the Below Zero beginner guide, which covers base power supply setup (Solar Panels vs Thermal Plants) and how your base’s power system relates to your Seatruck recharging routine.
The Seatruck as a Mobile Base Strategy
One of the most effective Below Zero strategies is treating the Seatruck not as a vehicle but as a mobile forward base. With the right module combination, the Seatruck can support extended missions far from your permanent base:
- Attach the Fabricator Module for on-the-go crafting — repair materials, food, and equipment can all be crafted mid-mission
- Attach the Sleeper Module to time-skip and recover health without returning to your base
- Attach the Storage Module for extended resource collection before returning to base
- Attach the Aquarium Module to maintain a live food supply — useful for very extended missions
The combination of Fabricator + Sleeper + Storage turns the Seatruck into a fully self-sufficient mobile operation that can sustain multi-hour exploration sessions in deep biomes without requiring trips back to your permanent base. This is particularly useful for the mid-game Crystal Caves exploration where the distance from base to target area makes frequent return trips time-consuming.
Seatruck vs Prawn Suit: Decision Framework
The single most common question Below Zero players have about vehicles is when to use the Seatruck versus the Prawn Suit. Here is a clear decision framework:
- Use the Seatruck for: transit between locations, ocean biome exploration, carrying equipment and modules, any situation where speed and enclosed operation matter
- Use the Prawn Suit for: cave navigation (too tight for the Seatruck), drill mining of large mineral deposits, the Crystal Caves endgame area, situations where the Seatruck’s bulk is a liability
- Use both together via the Docking Module: standard end-game configuration — the Seatruck carries the Prawn Suit to the area, then you switch to the Prawn Suit for the final approach and objective completion
For a broader view of how Below Zero’s vehicle system compares to the original Subnautica’s Seamoth/Cyclops/Prawn setup, the Subnautica vehicle progression guide explains the design philosophy differences between the two games’ approaches to underwater transport. And if you are playing Below Zero as preparation for Subnautica 2, the Subnautica 2 preparation guide explains which skills from Below Zero transfer directly to the sequel.
More Subnautica Below Zero Guides
- Subnautica Below Zero Beginner Guide
- Cold Suit and Land Survival Guide
- Delta Station Guide — The Early Game Route
- Al-An and the Architect Body Guide
- Marguerit Maida and Omega Lab Guide
- Seatruck Guide — Modules and Upgrades
- Best Base Locations in Below Zero
- Creature Survival Guide
- Accessibility and Interactable Items Guide
- Full Playthrough Watch Order
- Subnautica vs Below Zero — Which to Play First?
- Subnautica Below Zero Hub — All Guides
