Barotrauma: Complete Guide

A guide to surviving Europa in Barotrauma: every job and what it actually does, running the reactor, fixing leaks, the medical system, piloting and sonar, monsters, campaign economy and submarine upgrades, plus what changed in the 2026 updates and the upcoming Home & Harbor DLC.

Researched September 2026 — current as of v1.13.4.0 (Summer Update 2026 hotfix, 18 June 2026). Live games change; check the linked sources if something differs.

Where the Game Is Now

• Spring Update 2026 (v1.12.6.2, 9 April): reworked Tier 1 subs (Barsuk, Dugong, Orca, Camel), added pipe weakpoints and valves to Orca and Camel, let you drop characters and monster corpses into a deconstructor, buffed flares and glowsticks as monster distractions (and nerfed the Sonar Beacon), cut the default respawn timer from 300 to 30 seconds, and made characters no longer drop items when a player disconnects. Hotfix v1.12.7.0 followed on 21 April.
• Summer Update 2026 (v1.13.3.1, 16 June): reworked Tier 2 subs Humpback, Orca 2, Azimuth, Typhon and Herja (the Orca 2's command room is now central; the Typhon has valves and pipe weakpoints; the Herja has a power distributor). You can now back up custom subs to Steam Cloud from the sub editor's save dialog. Hotfix v1.13.4.0 (18 June) fixed crossplay and the Herja railgun bot issue.
• Home & Harbor Expansion (paid DLC) is announced and has a Steam store page listing a 2026 release, but no exact date or price yet. Developers said "later this year" in April 2026; it adds base building and management features and content about the Descendants.

Quick Start

• Start a single-player campaign with bots before playing multiplayer. You can give orders to bots and learn every station.
• Learn your job first. Each job has specific stations and tools. Don't try to do everything.
• The reactor powers everything. No power means no engines, no pumps, no oxygen generator.
• Wear a diving mask or suit when water rises. Flooding and low oxygen kill fast.
• Weld hull breaches with a welding tool (needs a welding fuel tank). Repair broken devices with the right tools and skill.
• Use the Health interface (H) to check injuries and treat them.
• Talk. In multiplayer, report leaks, fires and monsters. Communication is the game.
• Carry an oxygen tank and a spare battery or fuel. They save lives.
• Stay inside the sub at depth unless you have a diving suit. Outside water pressure crushes you without one.

Default PC Controls

Action | Key

Use / interact | E

Toggle inventory | Q

Health interface | H

Crew orders menu | C

Command interface (quick orders) | Middle mouse

Grab / drag a character | G

Run | Left Shift

Crouch | Left Ctrl

Ragdoll | Space

Push-to-talk voice | V

Text chat | T

Crew and info tab | Tab

All of these can be rebound in Settings.

Your First Campaign Mission, Step by Step

• Before undocking: Check the reactor has fuel rods and automatic control is on. Grab a diving mask, an oxygen tank and your job's tools (wrench, screwdriver, welding tool). Check the cargo you're delivering is loaded.
• Undock and set a course: At the navigation terminal, select the destination and enable auto-pilot. Keep speed moderate; ramming walls damages the hull.
• Watch the sonar: Monsters appear as moving blips. Tell the crew (or order bots) to man turrets when something big approaches.
• When something breaks: The status monitor shows damaged rooms and water levels. Send the Mechanic to breaches, the Engineer to junction boxes, and close watertight doors in flooded sections.
• Arriving: Slow down, line up with the outpost's docking port, and dock. Deliver cargo, collect pay, and spend on repairs, medicine and fuel before anything else.
• Between missions: Buy spare fuel rods, bandages, morphine and oxygen tanks. Upgrade the hull and pumps before turrets on your first couple of runs.

Commanding Bots

• Open the command interface to give orders: operate reactor, man turrets, fix leaks, fix electrical/mechanical devices, pump water, fight intruders, follow, wait.
• Give each bot one standing job that matches its class. An Engineer bot on "operate reactor" and a Mechanic bot on "fix leaks" covers most emergencies.
• Bots can't read situations well. Check on them after big hits.

Jobs

Job | Role | Key stations and tools

Captain | Command, piloting, sonar | Navigation terminal, sonar, periscopes

Engineer | Reactor, power, electrical repairs | Reactor, junction boxes, screwdriver, wiring

Mechanic | Mechanical repairs, hull, pumps, engines | Wrench, welding tool, plasma cutter, fabricator

Medic | Healing, drugs, surgery | Health interface, medical fabricator

Security Officer | Weapons, defending crew | Turrets, coilguns, railguns, handcuffs

Assistant | Help anywhere, learn skills | Anything

Each job has three specialisation talent trees. Gaining XP unlocks talents that make you better at your role.

Reactor Basics

• Fuel: Insert fuel rods into the reactor. The rods deplete over time.
• Fission Rate produces heat; Turbine Output converts it into power.
• Match output to load. The reactor screen shows power load; set turbine output so output matches load.
• Automatic control works fine for most situations. Turn it on if you're unsure.
• Temperature: Keep it in the safe zone. Too high means a meltdown; the reactor explodes.
• Overvoltage: Too much power damages devices and junction boxes. Too little makes systems fail.

Leaks, Flooding and Oxygen

• Hull breaches let water in. Mechanics fix them with welding tools; engineers help.
• Pumps remove water. Set them to pump out in flooded rooms.
• Oxygen generator: Produces oxygen for the whole sub. Needs power.
• Diving masks give short-term oxygen; diving suits protect against pressure and water.
• Oxygen tanks power masks and suits. Carry spares.
• Watertight doors: Close them to contain flooding.

Medical System

• Open the Health interface (H) to see limb injuries: bleeding, burns, blunt trauma, lacerations, oxygen low, and more.
• Common treatments:

Problem | Treatment

Bleeding | Bandage

Pain / trauma | Morphine or other painkillers

Blood loss | Saline or blood packs

Opiate overdose | Naloxone

Husk infection | Calyxanide

Suffocation | Get the patient oxygen; use CPR if unconscious

• Skill matters: Low Medical skill makes treatments less effective. Let the Medic handle complex cases.
• Fabricate medicine at the medical fabricator using materials from outposts or looted wrecks.

Piloting and Sonar

• Navigation terminal: Steer, set destination, use auto-pilot, or "maintain position".
• Sonar shows terrain, monsters and other subs. Active sonar reveals you to monsters; passive sonar is quieter.
• Ballast: The sub rises and sinks through ballast tanks. Keep ballast pumps working.
• Docking: Dock at outposts and stations to trade and accept missions.

Monsters

Monster | Threat | Tip

Crawler | Weak but swarms | Melee or small arms

Mudraptor | Breaks into subs | Security with guns

Husk | Infects crew | Keep Calyxanide on hand

Hammerhead | Rams the hull | Turrets

Tiger Thresher | Fast, aggressive | Turrets, stay alert

Moloch | Large, tanky | Heavy turrets, avoid when possible

Watcher | Psychosis effects | Stay out of range

Charybdis | Huge predator | Avoid; big turrets

Endworm | Massive boss | Late-game railguns

Latcher | Grabs the sub | Heavy weapons

Campaign

• Missions: Deliveries, monster hunts, salvage, escort, and more. Pay money and reputation.
• Outposts: Trade, hire crew, upgrade your sub, buy new subs.
• Factions: Reputation with factions (Coalition, Jovian Separatists, Children of the Honkmother, the Husk cult) opens missions and events and changes prices.
• Biomes: From the Cold Caverns to the Europan Ridge, the Aphotic Plateau, the Great Sea, and the Hydrothermal Wastes. Each goes deeper and is more dangerous.
• Submarine upgrades: Hull, engines, turrets and reactor upgrades at outposts. Tier 1 subs (Barsuk, Dugong, Orca, Camel) are starters; Tier 2 (Humpback, Orca 2, Azimuth, Typhon, Herja) are mid-game.

Game Modes

Mode | Description

Single-player campaign | You and bots

Multiplayer campaign | Up to 16 players

Sandbox | Free play

Mission | One-off missions

PvP | Crew vs crew

Traitors (server option) | Hidden saboteurs; enabled per multiplayer server rather than as a separate mode

Common Mistakes to Avoid

• Running the reactor too hot. Meltdowns end campaigns.
• Ignoring overvoltage. It breaks junction boxes and devices.
• Leaving hatches open during flooding. Close watertight doors.
• Not carrying oxygen. Suffocation is the most common death.
• Using active sonar constantly. It attracts monsters.
• Letting unskilled crew do medical or engineering work. Skill matters.

Advanced Tips

• Wiring: Learn basic wiring (junction boxes, relays, logic components). You can automate systems like pumps and lights.
• Talent synergy: Build crew talents around your sub's needs; a Mechanic with repair talents saves lives.
• Stealth runs: Some subs (like the Azimuth) have stealth circuits; the Summer Update tweaked the Azimuth's stealth mode circuit.
• Distractions: Flares and glowsticks are better monster distractions since the Spring Update.
• Deconstructor use: Drag corpses into the deconstructor to clean the sub and get materials.
• Back up custom subs: Use the Steam Cloud checkbox in the sub editor.

FAQ

What's the latest version? v1.13.4.0 (18 June 2026), the Summer Update hotfix.

When is Home & Harbor coming out? No exact date yet. The Steam page lists it as a 2026 release with no price; the devs said "later this year" in April 2026.

How do I stop the reactor melting down? Match turbine output to power load, or use automatic control. Watch the temperature.

What's the best job for beginners? Assistant or Mechanic. Both teach the sub's layout and repairs.

How do I cure husk infection? Calyxanide.

Can I play solo? Yes. Single-player campaign uses bots you command.

How many players can play? Up to 16.

Sources

• Barotrauma on Steam
• Steam News: Barotrauma
• Barotrauma: Home & Harbor Expansion on Steam
• Barotrauma source: default key bindings (GitHub)