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.
Circa March 21-24, 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.
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 also 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.|
|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.|
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.