A diving chamber is a vessel for human occupation, which may have an entrance that can be sealed to hold an internal pressure significantly higher than ambient pressure, a pressurised gas system to control the internal pressure, and a supply of breathing gas for the occupants.
The decompression chamber at the Neutral Buoyancy Lab
Two United States Navy sailors inside a decompression chamber about to undergo training
One person chamber
Control panel of a basic deck decompression chamber
A breathing gas is a mixture of gaseous chemical elements and compounds used for respiration. Air is the most common and only natural breathing gas, but other mixtures of gases, or pure oxygen, are also used in breathing equipment and enclosed habitats. Oxygen is the essential component for any breathing gas. Breathing gases for hyperbaric use have been developed to improve on the performance of ordinary air by reducing the risk of decompression sickness, reducing the duration of decompression, reducing nitrogen narcosis or allowing safer deep diving.
Sailors check breathing devices at sea.
A closed bell used for saturation diving showing emergency gas supply cylinders
2% Heliox storage quad. 2% oxygen by volume is sufficient at pressures exceeding 90 msw.
Electro-galvanic fuel cell as used in a diving rebreather