Subnautica Mobile Vehicle Bay — Fragments & Recipe Guide

The Mobile Vehicle Bay is the deployable construction platform in Subnautica that builds every vehicle in the game — the Seamoth, the Cyclops, the Prawn Suit and the Neptune Launch Platform. You unlock it by scanning 3 fragments found in Kelp Forest, Grassy Plateaus and Safe Shallows wrecks and supply crates, then craft it in the Fabricator for 1 Titanium Ingot + 1 Lubricant + 1 Power Cell. This guide covers every fragment source, the full recipe chain, what each vehicle costs at the bay, and the deployment tricks worth knowing.

Here's what you'll learn:

• Every Mobile Vehicle Bay fragment location, ranked by how early you can reach it
• The recipe and how to craft each of its three ingredients
• What each vehicle costs to build at the bay (with the linked vehicle guides)
• Deployment tips, including the Moonpool trick and how to pick it back up

Official resources: Steam store page · Official Subnautica Wiki — Mobile Vehicle Bay · IGN Subnautica page

What Is the Mobile Vehicle Bay?

The Mobile Vehicle Bay is a deployable item that occupies 9 inventory slots (3×3). When you release it in the water, it floats to the surface, unfolds into a small platform, and you board it to open the vehicle-construction interface. Four fabrication drones hover out of the platform and build the vehicle in front of it, showing progress the same way the Habitat Builder does.

The databank entry frames it as standard Alterra equipment:

Per the official Subnautica Wiki — Mobile Vehicle Bay: "The mobile vehicle bay is a deployable station equipped with fabrication drones, designed to construct small research and exploration vehicles from raw materials. It is a common tool in almost all industrial, scientific and colonization operations."

One important difference from the Habitat Builder: the bay requires the materials in your inventory before construction starts — you can't place a blueprint and fill it later, which the official wiki calls out explicitly.

Where to Find the Mobile Vehicle Bay Fragments

You need to scan 3 fragments (they're stored in one fragment item in your inventory until you've scanned three). The official wiki lists them on the seabed, in wrecks, and in crates across the Kelp Forest, Grassy Plateaus and Safe Shallows:

There's no depth or vehicle requirement for any of these — a Seaglide and a knife are enough. If you're coming up short, build a Scanner Room over the Kelp Forest and scan for fragments; the blips make the last one trivial to find.

Mobile Vehicle Bay Recipe

Craft it in the Fabricator with:

The two sub-chains matter because they need specific plants:

• Lubricant — harvest a Creepvine Seed Cluster from the glowing pods on Kelp Forest Creepvines.
• Power Cell — craft 2 Batteries (2 Acid Mushroom + 1 Copper Ore each), then 1 Silicone Rubber (1 Creepvine Seed Cluster), then combine.
• Titanium Ingot — 10 Titanium from metal salvage, limestone outcrops and scrap.

Full raw cost: roughly 10 Titanium, 2 Creepvine Seed Clusters, 4 Acid Mushroom and 1 Copper Ore.

What You Can Build With the Mobile Vehicle Bay

All vehicles in the game are built at the bay. Official wiki crafting tables:

Building each vehicle also ticks off achievements: Personal Propulsion (Seamoth), Ordered the Prawn (Prawn Suit) and 40-foot Sub For One (Cyclops). For the full rundown on the two big ones, see our Cyclops guide and Prawn Suit guide — both cover the upgrades you'll want after the base vehicle rolls off the bay.

Deployment Tips

• Deploy at the surface: the bay floats up and unfolds; vehicles are built at the water line. In the Safe Shallows this is harmless, but in deeper biomes the bay bobs around — keep an eye on where it drifts.
• The Moonpool trick: per the official wiki, you can deploy the bay directly under a Moonpool, which lets you construct vehicles at depth without surfacing. It's a documented and widely used technique for deep forward bases.
• Pick it back up: look at the metal platform and press the interact key — the bay packs back into a 9-slot item so you can carry it to the next base.
• Materials must be in your inventory: unlike the Habitat Builder, the bay won't place a ghost blueprint and fill it later. Bring everything for the vehicle you're building.
• It's not a vehicle: you can't pilot the bay, and it has no health worth mentioning — don't expect it to survive aggressive fauna, though it's generally ignored.

FAQ

Where are the Mobile Vehicle Bay fragments in Subnautica?

In the Kelp Forest (wrecks and crates, including a cluster near the Creepvine at roughly -306, -51, -57), the Grassy Plateaus and the Safe Shallows. You need 3 fragments total.

What is the Mobile Vehicle Bay recipe?

1 Titanium Ingot + 1 Lubricant + 1 Power Cell, crafted in the Fabricator. Below Zero instead uses a Computer Chip — don't mix the two games up.

How many fragments do you need for the Mobile Vehicle Bay?

Three. Once scanned, the blueprint unlocks and the bay becomes craftable at any Fabricator.

What can you build with the Mobile Vehicle Bay?

The Seamoth, the Cyclops, the Prawn Suit and the Neptune Launch Platform (endgame rocket). It's the only way to construct any of them.

Do you need the Mobile Vehicle Bay to build the Seamoth?

Yes — the Seamoth is constructed at the bay, not at a base. Get the bay fragments and craft the bay first, then use it to roll out your first Seamoth.

Related Guides

• Subnautica Cyclops — Full Guide
• Subnautica Prawn Suit — Deep Mining Setup
• Subnautica Multipurpose Room — Base Building Guide
• Subnautica Walkthrough — Full Story Progression

Last updated: August 13, 2026.