Barotrauma Submarine Systems Guide: Power, Drainage, Oxygen and Repairs
Uses the Dugong to diagnose stopped reactors, junction boxes, pumps, Oxygen Generators, engines and turrets. Explains normal displays, tools, post-repair checks and wiring differences between submarines.
Edition: Normal PC Steam base game, app 602960, without mods. Covers the opening Campaign and basic/job tutorials. Uses the standard Dugong, approximately Normal difficulty and Jovian Radiation off. Distinguishes solo AI from co-op; individual talents, Workshop submarines, the late game and special modes are treated separately.
Verification scope: Public sources compared on 2026-10-04. The latest base-game patch confirmed through official Steam was v1.13.4.0, dated 2026-06-18. Home & Harbor is an upcoming, unreleased expansion. The game has not been launched; the current Japanese UI and reproduction of all wiring have not been checked.
Sources checked: 2026-10-04
49 / 49 rows
Determine whether power loss is submarine-wide or local
Before increasing reactor values when devices stop, check the extent of the outage. If several stop together, investigate their shared power source; if only one stops, inspect that device and its connections first.
Wide tables scroll horizontally.
| Failure chain | Upstream and downstream checks | Assigned task | Exception |
|---|---|---|---|
| Multiple devices stop across the submarine | Reactor, main junction boxes, then individual devices | Check power, fuel and condition in order | Some submarines temporarily run selected devices from batteries alone |
| One compartment is dark or stopped | Devices in that compartment and their connections | Inspect the relevant junction box, flooding and individual switches | Working lights alone do not prove adequate power |
| Cannot move horizontally | Steering input, Engine, then power | Check manual/automatic control, engine condition and signals | Inspect obstacle collisions separately too |
| Cannot move vertically | Steering input, ballast Pump, then water level | Distinguish ballast water from flooding elsewhere | Forcing all pumps to drain interferes with normal steering |
| Poor air inside | Power, Oxygen Generator, Vent, then room | Check generator condition and connected vents | Suit tanks are managed separately |
| Aiming works but firing does not | Periscope, turret, Loader and Supercapacitor | Check ammunition and firing power separately | Repairing power will not fix a target outside the turret's firing arc |
| Breaks again immediately after repair | Water, fire, overvoltage or outside attacks | Address the cause before restoring condition | Distinguish normal condition loss from sudden repeated failures |
No matching entries in this table. Shorten the query or clear it to restore all entries.
Arrows in the table show inspection order, not actual wiring or electricity flow speed. On modified submarines, prioritize the original wiring and device explanations.
Start the Reactor with Automatic Control and Distinguish Heat from Output
For the early standard Dugong, the basic example uses automatic control to learn behavior before manual optimization. Power on, fuel available and sufficient output reaching devices are separate conditions.
- Open the reactor and inspect condition and fuel slots. Empty rods produce no heat, so prepare a normal Fuel Rod with contents remaining
- For practice, begin with one normal Fuel Rod and switch on Power. This simplifies initial handling; it is not an official required rod count for every submarine
- Enable Automatic Control and check its indicator. Do not directly apply this to modified submarines with separate automatic-control circuits
- Wait for temperature and Output/Load to change, then check pumps, engines and oxygen devices. Response to a load change is not instantaneous
- If heat warnings persist, do not add another rod; have the operator check output, fuel and control method. For dangerous overheating, coordinate switching Power off and preparing for the resulting outage
Wide tables scroll horizontally.
| Display or state | Distinction in meaning | Inspection |
|---|---|---|
| Fuel Out / empty contents | No fuel capable of generating heat | Fuel rod contents and type |
| Output Low | Supply cannot meet load | Startup delay, fuel, condition or a sudden load increase |
| Output High／Critical Output | A balance problem between supply and Load | Has load dropped suddenly, for example during deceleration? |
| Overheat／Critical Heat | The reactor's temperature itself is high | Added fuel and Fission/Turbine balance |
| SCRAM | Heat may remain even while stopped | Check Power state and falling temperature |
No matching entries in this table. Shorten the query or clear it to restore all entries.
"High output" and "reactor overheating" are not the same warning. Automatic control can handle multiple rods, but adjustment may lag just after one is added. Filling every spare slot on your first try is not the procedure used here.
Inspect Junction Boxes and Batteries
Wide tables scroll horizontally.
| Device or symptom | Normal-state reading | Required items or connections | Action | Recovery check and submarine differences |
|---|---|---|---|---|
| Junction Box | Receiving power and retaining condition | Screwdriver and upstream connection | Check Power and Load after Repair | The Powered light alone does not prove correct output |
| Junction box repeatedly breaks | No overvoltage or flooding | Load changes and surrounding water/fire | Stop the cause before repairing | Distinguish the red Overvoltage display from actual damage |
| Battery empty | Contents and charge level increase | Power supply, charging setting and condition | Check charging rate and the supply source too | Stored capacity may feed a separate circuit |
| Backup power does not work | Contents available and output destination enabled | Submarine-specific switches and connections | Inspect that submarine's switching display | Do not assume every submarine has the same Emergency Battery button |
| Power fluctuates whenever you decelerate | Sudden load changes settle | Engine and reactor response | Avoid abrupt acceleration or deceleration and report changes to the operator | Observe supply changes relative to demand |
No matching entries in this table. Shorten the query or clear it to restore all entries.
Overvoltage damage thresholds differ between the defaults in an older personal source and values in standard-submarine Wiki pages. Check the submarine's warnings and condition instead of memorizing a universal ratio.
A Flashing Pump Light Suggests Missing Power
Ballast compartments take water in and out to help vertical movement. Water itself is not a fault; check whether it changes with steering commands.
Wide tables scroll horizontally.
| Device or symptom | Display meaning | Required connections or items | Action | Recovery check and submarine differences |
|---|---|---|---|---|
| Power light steady | Power supplied and device switched on | Upstream supply | Watch flow and water level | A steady light does not necessarily mean draining |
| Power light flashing | Switched on but missing required power | Junction boxes and reactor | Repair or inspect upstream | Light becomes steady and water level changes |
| Power light off | Pump switched off | Device Power and control | Check the switches required on that submarine | Check the presence of power separately |
| Automatic Control light on | Receiving a control signal | Signals from steering, water detection or similar controls | Inspect the original control source | Moving the dial alone may be overridden |
| Room with manual drainage | Negative flow drains | Wrench and power supply | Select negative flow on a pump without an automatic signal | Water level falls; 0 stops flow |
| Water remains after holes are sealed | Recheck inflow, drainage route and pump | Doors, other holes and downstream drainage | Restore operation by checking one cause at a time | The Dugong oxygen room has no passive drainage |
| Submarine will not rise | Flooding outside ballast and ballast water level | Hull repairs, pumps and power | Stop inflow first, then compare steering with water level | Engine repair alone does not restore buoyancy |
No matching entries in this table. Shorten the query or clear it to restore all entries.
This guide does not recommend forcing every pump to maximum drainage or disconnecting unfamiliar wires. Mechanical repair of the pump and using a Screwdriver on its connection panel are separate actions.
Distinguish a Running Generator from Breathable Air in a Room
Wide tables scroll horizontally.
| Symptom | Inspect first | Action | Recovery check |
|---|---|---|---|
| Oxygen falls in several rooms | Generator power and condition | Restore power and make necessary repairs with a Wrench | Room oxygen display recovers |
| Only certain rooms are low | Vent links and compartment state | Check local ventilation, fire and access | Recheck the affected room's reading |
| Tank does not refill | Compatible device and available power? | Insert into a compatible slot such as the generator's | The tank's own contents increase |
| The room is normal but only I cannot breathe | Worn mask or suit | Replace the tank inside that gear | Check the breathing tank and health condition |
| Oxygen reading unavailable | Oxygen data input to the Status Monitor | Check sensors and connections | Do not read a missing display as 100% |
| Water remains only around the generator | Dugong drainage route | Inspect the room and drainage route with safe equipment | Check flooding itself separately from oxygen output |
No matching entries in this table. Shorten the query or clear it to restore all entries.
An individual reference states that the standard Oxygen Generator does not deteriorate from flooding alone. Instead of assuming submersion must have broken it, inspect junction boxes, supply, condition and ventilation separately.
Check Turret Aiming, Ammunition and Power Separately
Wide tables scroll horizontally.
| Device or symptom | Normal display | Required connections or items | Action | Recovery check and submarine differences |
|---|---|---|---|---|
| Periscope | View and aim of the assigned turret | Control connection to the turret | Open its assigned periscope | Check that you are not operating the adjacent turret |
| Coilgun Loader | Compatible ammunition box and contents | Loader linked to the Coilgun | Replace an empty box with compatible ammunition | You can inspect the loading side without going outside |
| Supercapacitor | Charge remaining | Upstream power, charge rate and condition | If empty, check charging and upstream supply | Wait for recharge after sustained fire. Setting charge speed above 70% reduces condition |
| Turret cannot turn toward the enemy | Firing arc and enemy/ally positions | Secure a firing line | Coordinate position with the Captain | Do not force shots into the submarine's blind spots |
| AI does not fire | Orders, assigned turret, visibility and ammunition | Check Operate Weapons on the intended turret | Correct priority orders and resupply if needed | An order alone does not guarantee hits |
| An ally is returning | Airlock area and firing line | Share the area where firing must stop | Aim away from the ally | Some Dugong turret positions can reach the airlock |
No matching entries in this table. Shorten the query or clear it to restore all entries.
This table uses the standard Coilgun. Other turrets do not work with the same ammunition box. Best ammunition and shot counts for every enemy are outside scope.
Post-Repair Checks Help Reduce Repeated Failures
Wide tables scroll horizontally.
| Repaired item | Check after condition | If still stopped | Tool to use |
|---|---|---|---|
| Reactor | Power, fuel and Automatic Control | Heat, Output/Load and the upstream operator's actions | Screwdriver |
| Junction Box | Powered and upstream supply | Flooding, fire, overvoltage and connections | Screwdriver |
| Pump | Power light, direction and automatic control | Inflow, drainage destination and power | Wrench |
| Engine | Steering input and power | Terminal mode, connections and obstacles | Wrench |
| Oxygen Generator | Power and room oxygen | Vent links and room fires | Wrench |
| Loader | Compatible ammunition box and turret | Empty boxes, links and firing power | Wrench |
| Outer hull | Other holes and water level | Doors, pumps and inflow from other compartments | Welding Tool and fuel |
| Battery／Supercapacitor | Contents and charge rate | Power, output destination and submarine-specific switches | Screwdriver |
No matching entries in this table. Shorten the query or clear it to restore all entries.
To avoid adding faults during an emergency, choose one system to restore before acting. This guide suggests confirming recovery, then moving to the remaining symptom.
Dugong Example: "The Hole Is Sealed, but We Still Cannot Rise"
This is a hypothetical diagnostic example combining public rules, not a gameplay report. Suppose the engine-room hole has been sealed but the submarine will not rise.
- Use General Status to inspect other compartments as well as the engine room. If water or another hole remains, stop inflow first
- Open the ballast pump. If Power flashes, investigate the power source before adjusting flow
- Find the stopped section using Electrical View and junction boxes, then repair with a Screwdriver if needed. Continue addressing causes wherever water remains
- Check steering state, such as Maintain Position, and see whether ballast water changes in response to your intended input
- Once restored, check oxygen, equipment and fuel for the next fault. No repair time or success rate is assumed
The example is for finding which part of inflow, drainage, power or steering still fails, rather than forcing every symptom into a single fault.
Frequently asked questions
The reactor is on, but the submarine will not move
Inspect fuel, Output/Load, junction boxes and stopped-device condition. For horizontal movement, check Engine and steering input; for vertical movement, distinguish ballast from flooding in other compartments.
The pump's Power light flashes
Public sources describe this as switched on but without power. Check the connected junction boxes and reactor before increasing the flow dial.
Does submersion always break the Oxygen Generator?
The individual standard-device reference says flooding does not cause deterioration. Separately check surrounding junction-box faults, inadequate supply and pre-existing low condition.
Can someone with a different job repair things?
Normal repairs can be done with suitable tools and skills. Below the required skill, repairs are slower and failures can cause injury, so normally assign a skilled crew member.
Are there reactor or wiring values that work on every submarine?
Values vary with device settings, load, wiring and upgrades. This guide gives no fixed optimum; diagnose using that submarine's displays and connections.