Underwater diving safety equipment

self-contained, short-term light-source

mixture

underwater instrument to record dive depth over time profile and to calculate decompression obligations in real time, typically carried on a diver's wrist

diving equipment for controlling buoyancy by volume adjustment

gauge that indicates the depth underwater, primarily used by divers and on submarines

watch designed for underwater diving

technique to measure pressure

Heliox is a breathing gas mixture of helium (He) and oxygen (O2). It is used as a medical treatment for patients with difficulty breathing because this mixture generates less resistance than atmospheric air when passing through the airways of the lungs, and thus requires less effort by a patient to breathe in and out of the lungs. It is also used as a breathing gas for deep ambient pressure diving as it is not narcotic at high pressure, and for its low work of breathing.

breathing gas mixture experimentally used for very deep diving

methods used by underwater divers to communicate

Flag signal indicating divers are in the water nearby

buoy used by scuba divers to indicate the diver's position to their surface safety boat

device which produces a voltage by a chemical reaction with oxygen proportional to partial pressure