Breathe Safely and Smoothly. This new crop of regulators, octos and safe seconds ensures you never have to worry about where your next breath is coming from — just take a sip, and glide into your next underwater adventure.
What You Need to Know: Scuba Regulators
Regulators have two stages — the first stage, attached to the tank valve, breaks the high-pressure air down to intermediate pressure. The second stage — in the diver’s mouth — reduces the intermediate pressure to ambient pressure, the exact pressure you need to breathe comfortably underwater.
First stages are either piston, which are open to the water, or diaphragm, which are closed. Piston regulators have fewer moving parts, usually making them easier to service and sometimes less expensive to purchase, and are more compatible with swivels for easier hose routing. Diaphragm regs are better for use in very cold or dirty water, which also means they can potentially be serviced less often than piston regs.
Second stages come in various sizes and configurations; make sure yours is appropriate to your diving conditions —for example, have a large purge button if you generally dive in thick gloves or mitts. Second stages can be user-adjustable, most commonly with a dive/predive setting. Changing settings allows you to adjust the sensitivity of the air flow, preventing it from free-flowing, particularly useful in a strong surface current.