Regulator — What It Is and Why It Matters

A scuba regulator is the system that reduces high-pressure air from the tank to a breathable pressure. It consists of a first stage (attached to the tank valve) that reduces tank pressure to an intermediate pressure, and a second stage (the mouthpiece) that delivers air on demand at ambient pressure when you inhale. The regulator is the most critical piece of life-support equipment in scuba diving.

Regulators are rated for performance in cold water, at depth, and under high breathing demands. High-performance regulators breathe more easily at depth and resist freezing in cold conditions. Environmental sealing is essential for cold-water diving to prevent internal icing.