What Gases Are Used for Scuba Diving?

Scuba diving is an exhilarating and rewarding experience that allows us to explore the depths of the ocean. In order to do this safely and effectively, scuba divers rely on a range of tools and equipment, such as a specially-designed mask, fins, and air tanks. The air tanks are one of the most important pieces of gear for a diver, as it provides them with the air they need to breathe underwater. But what gases are used in scuba diving?

The most commonly used gas for scuba diving is compressed air, which is composed of nitrogen, oxygen and other trace gases. Compressed air is normally pumped into an air tank which is then worn by the diver. The pressure inside the tank varies depending on the depth of the dive – as divers go deeper underwater they require more pressure in order to breathe comfortably and safely.

Trimix is another type of gas which is used in scuba diving. It’s a combination of oxygen, helium, and nitrogen which can be adjusted depending on how deep the dive will be. Trimix can provide divers with more bottom time (the amount of time available to explore underwater) than compressed air alone as divers can adjust their gas mixture to suit their needs. This also helps reduce any risk associated with decompression sickness (also known as ‘the bends’).

Heliox is another type of gas used by experienced divers on deep dives due to its low density compared to other gases – this means that it takes up less space in a tank than other gases and gives divers more bottom time. Heliox also reduces any risk associated with decompression sickness.


In summary, the most commonly-used gas for scuba diving is compressed air which consists primarily nitrogen and oxygen. Trimix and heliox are also used for deeper dives due to their ability to provide longer bottom times or reduce risks associated with decompression sickness.

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Emma Gibson