An oxygen tank, sometimes referred to as oxygen cylinders due to their shape, is a specialized tank containing oxygen used primarily for breathing underwater. It is often used by the military for underwater insertions, although it can also be used for either mental recuperation for elderly citizens or physical recuperation for people who were left significantly injured.


Paz Ortega Andrade, real name Pacifica Ocean, used an oxygen tank while using Metal Gear ZEKE due to the cockpit flooding. Pacifica also was trained to use it under deep-sea diving training. She also used it even while forcibly expelled from ZEKE into the ocean, causing Big Boss to suspect the possibility that she had survived their battle.[1]

On March 11, 1984, various members of XOF were seen wearing oxygen tanks among their equipment while raiding the Dhekelia SBA Memorial Hospital in an attempt to kill Big Boss.

Circa March 21-24 1984, shortly after Kazuhira Miller's rescue from Da Ghwandai Khar and his being safely brought back to the new Mother Base, he was hooked up to an oxygen tank alongside an oxygen mask when placed onto a stretcher, in order to recuperate from the significant injuries that Miller had sustained while in captivity and presumably when he was ambushed by the Parasite Unit.

During the 1990s, FOXHOUND used oxygen tanks to train its operatives in diving and underwater infiltration. Solid Snake, during his FOXHOUND training, also managed to master this drill.

Outer Heaven and Zanzibar Land used oxygen tanks that were presumably used for work relating to waterways. Solid Snake, during the Outer Heaven Uprising and the Zanzibar Land Disturbance, made use of these during his missions after procuring them.

The lifeboats of the USS Discovery contained oxygen tanks so that it could supply even the ones not outside the boat with oxygen to ensure everyone's survival.

Solid Snake and Raiden used oxygen tanks when doing an underwater insertion into Shadow Moses Island and the Big Shell during the Shadow Moses Incident and the Big Shell Incident, respectively.

Solid Snake used an oxygen tank during the USS Missouri briefing during the Guns of the Patriots Incident, namely as a means of recuperating after his battle with Liquid Ocelot and his nearly being killed by Outer Haven.

Behind the scenes

The Oxygen Tank is an item that appears in the MSX2 games. In Metal Gear, its use is necessary for accessing the second part of Building 2 , which requires swimming through a large and deep waterway.

Game Item description for the Oxygen (O2) Tank Icon
Metal Gear Using the oxygen cylinder in the water will preserve your LIFE gauge. MG Oxygen Tank
Metal Gear 2: Solid Snake [Oxygen Tank] Doubles the length and slows the depletion of the O2 gauge underwater. Refills itself automatically when you surface. Oxygen

In the non-canon sequel Snake's Revenge, the Oxygen Tank returns, this time as a renewable procurable item akin to the rations, grenades, and ammunition boxes. These are used for the side-scrolling portions of the game, and a maximum amount of oxygen tanks are especially needed for the final side-scrolling portion of the game.

In Metal Gear 2: Solid Snake, its use is necessary for accessing the waterways underneath the Zanzibar building, in particular avoiding various mines while trying to locate the prison cell that Holly White was imprisoned inside.

Oxygen tanks do not make a playable appearance until the non-canon game Metal Gear Survive, where they act as an important item in the game due to it being required along with the gas mask to travel through areas covered with dust.

Notes and references

  1. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Briefing Files > Briefing Library > Chico > Love > Paz's True Self > The Mystery of Paz's Actions
    Snake (Big Boss): Besides, we [Snake and Chico] don't know for sure she's [Paz Ortega Andrade] dead. She was ejected into the ocean. And she had scuba equipment with her.
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