Barotrauma: Diving Guide for Beginners

Europan waters is not a friendly place, and divers encounter more workplace hostility than all other occupation onboard a submarine, if not from co-workers and the captain. Experienced divers are a rarity among submarine crew, even more so than less murderous medics. This guide is written to help those daunted by the dark depths of Europa cope with their fear and find more success outside the submarine.


With just the diving suit between your warm body and the cold ocean, exiting the (relatively) comforting confines of your submarine can be terrifying for even the most experienced crew. As such, new sailors and captains alike would often shy away from tasks that require a bit of EVA action. This guide is written to help those daunted by the dark depths of Europa cope with their fear and find more success outside the submarine.

Section One: Equipment

Knowing what to bring (and what not to bring) is the first step to any successful diving mission (citation needed). Familiarity with your gear is essential to ensure that water stays outside and your insides stay inside.

Diving Suit

Never leave the submarine without one, or barotrauma will kill you in seconds. This outerwear also offers some (but a bit less than adequate) protection against aggressive denizens of the deep. The helmet also provides short-range illumination, most likely your only light source. The combat variant upgrade offers better protection and mobility. At the same time, the abyss version is far more cumbersome. Still, it can withstand even more pressure and punishment, as well as reducing oxygen usage. The upgrades are essential (mandatory even) as one leaves the safe shallows of cold caverns and heads for deeper waters.


While you cannot wear a ballistic vest under the diving suit, protective clothing and headgear worn by security personnel and gunners can offer an extra layer of defense. In addition, the medic’s gear includes pockets for medical items and provides a bit of protection to boot.

Radio Headset

A powered headset is required for remote communication with the crew. The effective range of radio headset is 50 meters, beyond which the signal would start breaking up, and all contact is lost beyond roughly 100 meters. Divers should take extra precautions (such as equipping a sonar beacon, bringing appropriate weaponry and medical supplies) if required to venture beyond the radio communication range.


Preferably, this should hold essential items, including medicine, oxygen tanks, and spare ammo for your weapon, and should always be kept in person and restocked after each dive. The recommended contents can vary depending on the scenario, but the recommended contents are:

  • At least three oxygen tanks.
  • Two doses of morphine.
  • Two blood packs.
  • Two tubes of antibiotic glue.
  • Two doses of calyxanide.

Still, it’s just six more inventory slots at your disposal.

Plasma Cutter

The plasma cutter is arguably the essential tool for divers. It breaks down wreck doors and alien walls from a safer distance and eliminates specific cave hazards with ease. It’s also necessary for mining mineral deposits. It can be used as a weapon (albeit somewhat poorly) as a last resort. It requires oxygen tanks to function.


Can force open doors and hatches quickly and silently, also functions as a makeshift melee weapon. However, the use of this tool is discouraged (more details below on diving hazards).

Underwater Scooter

This handheld scooter helps you move faster in water and provides adequate illumination when moving. Requires batteries to function; however, carrying spare batteries should be unnecessary under most circumstances. Additionally, you can drag a body/unconscious crew with you while using a scooter.

Handheld Sonar

The sonar helps you find your way outside the sub, recommended for mining and exterminating nests, as they point you toward the cave entrance and your objectives. Requires batteries to function, but only active sonar consumes power.


When switched on, it broadcasts a signal that visible on sonars. It is recommended to activate and carry one in person when venturing away from the submarine. Doing so allows your crewmate to keep track and find you if you need assistance. In the worst-case scenario, it can help others recover your belongings and send them to your next of kin (provided they are people of good conscience).

Flashlight, Flare & Glowstick

Flashlights provide adequate illumination, can be handheld or worn as headgear, with the downside of shorter battery life than sufficient to last the entirety of most underwater operations. Flares give off a bright red light and a smoke trail. They can be thrown and will sink in water. Glowsticks give off a softer green light, can be thrown, and will remain floating in place when dropped (but can be carried away by water flow). Both can help to mark out trails and hazards in caves.

Oxygen Supply

Besides the regular supply of oxygen tanks, make sure you always have spare tanks in your toolbelt. Even the more experienced divers can leave without backup tanks occasionally. Oxygenite tanks last longer and allow for better mobility when used as a source of oxygen. Oxygenite shards can also be used directly as an oxygen supply in a pinch.


It can be tempting to bring as much firepower as possible, as the intuitive problem-solving method in oceans of Europa is shooting at it. However, it is not only discouraged but can also backfire spectacularly (no pun intended), and inventory space is very precious. The tried and trusted rule is to bring no more than what you need and no less than what you should.

Diving Knife
While not the most ideal weapon for self-defense, it’s a better option than the crowbar or a screwdriver if you happen to run out of ammo. The weapon shines when you need to rid the eggs in a nest or destroy various thalamus organs (more on what thalamus is later), saving valuable ammunition. The Morbusine-coated variant (Europan Handshake) is quite more lethal, as every stab applies the deadly poison.

Harpoon Gun
The harpoon gun is the most accessible weapon for non-security personnel. While each regular harpoon has slightly less impact than a revolver round, ammunition is readily available if a fabricator is on hand. In addition, the spears can be reused repeatedly (except for exploding harpoons).

Often overlooked, the revolver packs quite a punch for its small size, capable of killing a crawler with two or thee shots. While the damage and knockback on the weapon are far weaker than that of a shotgun up close, it has good accuracy in range, making it a decent weapon and a good companion in wrecks.

A reliable choice for self-defense and especially for crew members relatively untrained with firearms, shotguns are valuable for wreck salvaging and nest exterminating operations. In addition, the pump-action, double-barreled variant (Boomstick) can fire two rounds almost simultaneously, which produces a more significant knockback.

The sub-machine gun has a decent rate of fire but packs less damage and stopping power in each shot. However, the large magazine size more than makes up for it. The dark-colored variant (Deadeye Carbine) has improved accuracy. It is a well-rounded weapon for all scenarios, especially for killing unarmored targets in the water from a distance.

While being the easiest ranged weapon to operate, the regular version of the flamer does not work underwater. Moreover, it is liable to significant collateral damage when used inside the submarine. On the other hand, the variant (Prototype Steam Cannon) spews out high-temperature steam. Subsequently, it can be used underwater and does not set things on fire, making it an invaluable weapon against husks and swarms of leucocytes.

Explosive weapons are not recommended nor needed for most underwater tasks. Generally, they cause more chaos than good in the hands of the inexperienced. The grenade launcher is a heavy-duty weapon that divers should use with caution due to the potential collateral damage in the event of a misfire. As hand-thrown grenades sink in water and explode after three seconds, they are the most effective clearing eggs if they are stuck in places you cannot reach. Explosive charges require a detonator hooked up to a button (or any signal-transmitting device) to function, and gunners can use them to pack extra power into railgun shells.

Medical Supplies & Basic First Aid

Although this part technically belongs in section one, it is important enough to warrant a standalone chapter. While experienced medics are lifesavers in diving missions, it’s a luxury that most submarine crews do not have. The most reliable medic out there in the depths of Europa is yourself. All crew members can save lives if they have proper medication, even if they are not medical professionals. Below are the medical items with their respective uses that divers are recommended to carry in the toolbelt, ordered by effectiveness.

  • Internal Damage (bite wounds, lacerations, gunshot wounds):


Insufficient medical skills will easily cause opiate overdose, addiction and withdrawal, but the side effects from a single syringe wear off after a while. That being said, do not use multiple syringes in quick succession, as the results are often deadly for the patient.

  • Bleeding/Burns:

bandage/plastiseal/antibiotic glue

Opiates heal burns reliably as well, and unlike wound dressings above they are not limb-specific.

  • Blood Loss:

alien blood/saline/blood pack

Under most circumstances saline works fine to cure blood loss, but like bandages they are better for patching people up when their condition is stable. If a person is already critical and rapidly losing blood, a blood pack is far more preferable. Alien blood works in a pinch, but induces mild psychosis as a side effect.

  • Husk Infection:

broad-range antibiotics/calyxanide

Broad-range antibiotics also makes you more resistant to husk infections, with the side effect of moderate organ damage.

  • Critical Condition:

anabolic steroids (cause psychosis as a side effect)

This is often used when the patient has reached critical state, is constantly losing vitality, and there is little time to apply proper medication. A single shot of steroids would recover the patient from critical state and reduces further damage received. This does not cure them of their injuries however, and adequate medical help is still needed as soon as possible.

Basic First-Aid

Only perform first-aid when you are relatively safe and help yourself before helping others. Replenish blood loss, seal bleeding wounds, and finish by treating internal damage. If the patient is unconscious and suffering from oxygen deprivation, ensure the patient has a steady oxygen supply before performing CPR. Apply liquid oxygenite or anabolic steroids if the patient is in critical condition.

Husk Infection Treatment

A slight fever, sore throat, and muscle cramps are telltale signs of the first stage of veloncaps calyx infection. If you exhibit any symptoms above after getting bitten by a husk, take calyxanide or broad-spectrum antibiotics immediately. It might take two doses of calyxanide (and even greater dosage of antibiotics) to wipe out husk infection entirely after the patient show visible signs. If you are unsure whether you are infected, consult the ship’s medic (or anyone with a medicalHUD equipped).

Section Two: Common Diving Hazards and Coping Mechanisms
Europa has more ways to kill a man than the number of human beings residing under its icy surface. The following section highlights some common causes of causalities for divers and how one should go about avoiding your untimely demise.
Europa has more ways to kill a man than the number of human beings residing under its icy surface. The following section highlights some common causes of causalities for divers and how one should go about avoiding your untimely demise.

Environmental Hazards

The following part details environmental diving hazards commonly encountered by divers. Pay attention so you don’t end up as another waterlogged corpse floating around in the icy depths.

Your Submarine

It might come as a surprise, but getting too intimate with your submarine can be bad for your health. Swimming through a rotating propeller will shred you up while getting hit by the hull can cause a heavy concussion. There is also an impressive number of diving catastrophes each month involving divers getting crushed between submarines and Europa’s icy crust, with the unfortunate souls pinned to the outer hull by the moving vessel. Friendly fire is also a common occurrence amidst the panic and confusion during creature attacks when unlucky divers get caught in the middle of a crossfire. The golden rule for avoiding submarine-related injuries is to never exit or approach a moving submarine or a submarine under attack.

Ice Shards

These fragile crystalline growths shatter on contact, accompanied by a loud noise akin to breaking glass. While such an encounter at most leaves a diver unnerved and a nasty splinter or two, ice shard growths tend to run rampant in caves. They are commonly seen in Cold Caverns and the European Ridge and are notoriously known to block narrow passageways. Fortunately, they can be easily rid of by a bullet, a harpoon, or a tickle from the plasma cutter.

Exploding Mushrooms

Like ice spikes, these nasty little biological mines are more nuisance than an actual threat. Usually present in cave systems in the Great Sea, swimming too close to one will trigger an explosion that leaves a diver dazed with ringing ears. Still, they too could be quickly neutralised with the tip of a plasma cutter’s flare.

Gas Vents

These natural formations are a common sight throughout Europa, from the Cold Caverns to the reaches of Hypothermal Wastes. Although how the green gas emitted would drain the suit of oxygen is still subject to much conjecture, most people agree that divers should minimize their exposure to the gas. In addition, divers should always carry extra tanks when venturing into caves.


In richer and deeper waters of Europa, divers would often find long, branch-like plant growth protruding from cave walls. They slow down any divers swimming through them. While they seem nothing more than an unpleasant inconvenience, the actual dangers are best summed up in the words of an experienced diver:

“As I moved through them, thin fingers reached out, clamouring and grasping at my waist and ankles. I am forced to slow into a crawl, despite the frantic humming from my scooter. I peered into the gloom, not sure what is ahead of me or behind me. I can’t help but think about my colleague who was mauled to death in these parts by mudraptors, trapped by the same suffocating embrace. My wandering mind was pulled back by the beeping warning reminding me to swap in a fresh oxygen tank. The hiss of gas vents sounded almost welcome. Almost.”
———— Terrace Wallace, freelancer security officer, 31

Ice Walls

Ice spires are a common sight in Europa’s oceans, and divers would find chunks of black ice blocking the passage in caverns as well. While it is easy for a submarine to destroy large ice blocks with onboard weaponry, these blockages are often deep down in parts of the cave where the turret fire cannot reach. In this case, it requires divers to clear them with a plasma cutter.


There are two variants of drafts, the naturally occurring ones in Europa’s oceans often hindering submarine and diver movement, and those created by the sudden rush of water into a breached space, often following the breaking open a wrecked door or a section of ruins wall. The former would often push divers into other cave hazards mentioned above, while the latter can easily carry divers off their feet, sometimes directly into the arms of whatever is beyond the doorway or wall. Therefore, it is advised to clear cave hazards with a plasma cutter in caves and pay attention to creature noises when exploring wreckages and ruins. If you suspect dangers lurk behind the door you are about to breach, use a plasma cutter instead of a crowbar.

Creature Hazards

The following focus on creatures divers would commonly encounter on diving missions. Heavens forbid you encounter ones that are not on this list while outside the submarine, as the results are often deadly.


They are the most common variety of hostile fauna found in the Europan ocean. These grotesque creatures often appear in swarms, weak individually but can easily overwhelm divers in large numbers. However, they are easily distracted by corpses. Crawlers would happily feast on any dead bodies nearby, even their own kind: killing a few in a swarm often send the rest into a feeding frenzy.


Mudraptors are agile predators appearing alone or in small groups. They often have natural armour covering their heads and back but can be shattered with enough force. They are aggressive toward light sources and would pursue their prey relentlessly. Like crawlers, they are found in open waters, shipwrecks, and ruins. The shotgun is the preferred method to eliminate mudraptors.


Swift creatures that launch long spines at ships and divers from a distance, difficult to pin down. However, they are pretty fragile, and well-aimed shots from a coilgun or an SMG can dispatch them quickly.


These eel-like creatures appear in large swarms. The larger armored bone threshers lead the unarmored but agile tiger threshers in conjoined attacks. Do not let their sleek frame fool you, they can take quite a beating, and precaution is required if you try to take them on at close quarters, which would be the case if you are clearing out one of their nests.


There are three variants of Velonaceps Calyx infestation manifesting in creatures. The most common can be found inhabiting the long-decayed remains of an unfortunate diver, often found in wrecks. They are the most common vector of husk infection among the submarine crew. The less common but still naturally occurring type is the husk crawler, which sometimes appears in caves. Besides their rather unsettling appearance and the ability to pass on the Velonaceps Calyx parasite to divers, they are not much different from the regular crawler. The last kind, created by a human recently succumbing to husk infection, is arguably the most dangerous. These husks possess superior regenerating capabilities and steadily recover from all types of injury as long as they are alive, even in critical state. Ensure they are properly killed.

Fractal Guardian

Biomechanical creatures possibly engineered by those who once resided in the alien ruins scattered throughout Europa’s waters, they are sentinels found among the last traces of a forgotten civilisation. Despite their structural complexity, they are not as a significant threat as they appear to be, especially as they usually appear alone rather than in groups.


Hammerheads are large and swift predators, preying on smaller creatures and unfortunate submarines alike. While any sane person would not choose to fight hammerheads outside the submarine, the fight would come to you on rare occasions. Fighting hammerhead in open waters is a death sentence for the lone and unprepared diver. Instead, one should seek the safety of the submarine or caves and crevices where the hammerhead cannot reach as soon as possible and dress the bleeding wounds resulting from hammerhead attacks. Once safe, divers can then engage the hammerheads with ship weaponry or ranged personal weaponry.


Despite its large size and intimidating appearance, the watchers are, in fact, docile and gentle creatures. They are never aggressive towards the submarine or the crew and fleeing as soon as fired upon, leaving a trail of acidic blood in its wake. However, its gaze does more to satisfy its curiosity. Watcher’s gaze will inflict severe discomfort on human beings, resulting in nausea, vomiting, and extreme psychosis. Unconfirmed reports also indicate that other Europan creatures seem to be encouraged by the presence of Watchers, gaining increased movement and capable of withstanding more punishment. In addition, there have yet to be any instances of Europan creatures attacking a Watcher, suggesting the Watchers share a strange mutual relationship with other denizens of the deep.


Thalamus refers to wreckages overtaken by fleshy alien plant growths known as ballast flora. Encountering them is quite a harrowing experience for any sailor due to their unsettling attack patterns. The thalamus starts its attack by using the signature flesh guns to fire grappling tentacles that latch onto passing submarines and drag them in. Then, it uses the flesh spike, a sharp fleshy appendage, to pierce sub hulls in a single strike and inject terminal cells (small red cellar creatures with an explosive suicide attack) into the submarine. In addition, if the infested wreckage still has functional weapons, the thalamus will also use them to attack the submarine and crew. Furthermore, certain rooms in thalamus wreckage contain cell-spawners, which pump out leucocytes to deter anyone who ventures into its belly. However, entering the infested wreck and destroying the brain is what the crew must resort to if the thalamus traps their ship.

Section Three: Scenarios

As Dr. Happy, the famous medical columnist for the Europan, once remarked, the lack of proper schools has led to most submariners learning their trade on the fly. While an inept mechanic at most receives some painful lacerations, a novice diver could receive a one-way ticket to the afterlife on their very first dive. This section provides some basic instructions for different diving operations to better prepare new divers. Although experienced divers could perform most EVA tasks alone, a successful dive requires a team effort. Therefore, this section should also be read by the captain and the rest of the crew.

Basic Diving Routine

The submarine should be parked in a stable position, preferably on the seabed, to prevent the sub from sinking beyond radio range before the crew can muster a response. The captain should make sure the surroundings are clear of hostile creatures and inform everyone about who is going on the dive team, where the dive team is going, and the tasked goal. Preferably, someone should stay at the helm to ensure the submarine stays where it is and alert others in case of mechanical failures and creature attacks. Dive teams ideally contain two or three members. Larger groups would stretch medical supplies and require more effort from the captain or the team leader to keep everything in order. The divers should perform all routines as quickly as possible to minimize the risk to both the dive team and the sub. The captain should also make regular radio checks and only depart after everyone is accounted for.

Beacon Repair

Screwdriver, wrench, welder, a single fuel rod, three oxygen tanks

  • Use the welders to repair all hull breaches on the beacon station.
  • Inspect all installations and junction boxes, connect any loose wires.
  • Repair the reactor, put the furl rod in, switch on the generator, and turn on automatic controls.
  • Switch on the pumps and drain the station of water.
  • Repair junction boxes and other installations as needed.
  • Go to the sonar screen and switch on the active sonar.
  • Sometimes restoring the beacon signal would attract a swarm of crawlers. If this happens, remain inside the beacon station and let the rest of the crew deal with them using ship weapons.
  • Return to the ship and depart after all crawlers are eliminated.
Wreck Salvage

Plasma cutter, weapon, metal crate/duffel bag stuffed with toolbelts, three oxygen tanks
Before beginning a salvage operation, one must confirm whether the wreck is a thalamus. It is advised to kill a thalamus (rupturing its brain somewhere in the wreckage, usually with a melee weapon) before exploring. There typically are two ways to enter a wreck: from the top, where one could easily find preexisting hull breaches, or from the bottom, through a broken ballast tank or by cutting down an airlock door. The latter entryway is recommended if the wreck is infested by a thalamus, as most defensive installations of a shipwreck are on the topside. Proceed through each room in your own order and pace so that you do not get lost. It is vital to listen for creature noises in the wreckages, as they alert divers to dangers nearby. Prioritise fuel, medicine, firearms, and munitions. Dead bodies often contain extra supplies as well, and their shipwreck ID cards can be used to open doors and hatches without breaking them down. Take a crate (or a duffel bag, if available) filled with eight to twelve toolbelts to ensure to take all salvage with you in one go. Grab oxygen tanks off supply cabinets and diving suits should you forget to bring any with you.

Ruin Exploration

Plasma cutter, weapon, handheld sonar, underwater scooter, six oxygen tanks
Use the plasma cutter to breach the wall near one end of a corridor or enter through an alien door. Avoid motion sensors (small spherical installations with a blinking red light) and remove Alien Power Cells from Alien Generators to deactivate nearby traps. Search for alien chests and relic holders, and be prepared for the occasional creature encounter, including crawlers, husks, mudraptors, and fractal guardians. It has to be noted however that the loot yield from ruins can vary tremendously, with some ruins containing empty rooms, chests and relic holders.

Cave Exploration

Plasma cutter, weapon, medication, handheld sonar, sonar beacon, underwater scooter, six oxygen tanks
For beginner divers, sticking to one side of the wall and dropping glowsticks is an excellent way to prevent getting lost in unfamiliar cavern systems. Using a sonar beacon is also recommended. More experienced divers can find their way around with a handheld sonar alone. Keep an eye out for minerals and underwater plants and gather as needed. If required to clear creature nests inside caves, it is essential to pack sufficient ammunition and medical supplies. Firearms and anaerobic steroids are highly recommended. A diving knife or a harpoon gun can be used to rupture eggs quickly.

Thanks to JoyFish for his great guide, all credit to his effort. you can also read the original guide from Steam Community. enjoy the game.

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Post Author: Robins Chew

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