Atomic Aquatics ST1 Regulator

Both breathe through the same titanium second-stage design as Atomic's T3 flagship. The difference is the first stage: the B2 uses chrome-plated brass — Atomic's value pick with flagship performance — while the ST1 is machined from solid 316 stainless steel with roughly twice the strength of brass and corrosion resistance approaching titanium, and it comes factory-sealed and freeze-protected as standard. Choose the ST1 for cold water, heavy use, or maximum durability; the B2 covers everything else for less.

Every 2 years or 300 dives, whichever comes first — Atomic's officially published interval, and one of the longest in the industry (most brands require service annually or every 100 dives). Atomic also recommends a quick annual inspection by an authorized dealer between services. Over years of ownership, that service schedule is a real cost saving.

A limited lifetime warranty for the original owner — and unusually, Atomic states the warranty is NOT contingent on proof of service. All titanium and metal parts are additionally warranted against corrosion for life. To activate it, register within 30 days of purchase, and buy from an authorized Atomic dealer (purchases from us qualify). Wear items like mouthpieces, hoses, and o-rings carry a 2-year warranty.

Follow the interval in your regulator's manual, since manufacturers commonly specify an annual inspection or a set number of dives and many warranties depend on it. A regulator is life-support equipment, so service belongs with a factory-trained technician rather than being attempted at home. Have it looked at sooner than scheduled if you notice increased breathing effort, free-flow, bubbles, or water in the second stage.

Make sure the dust cap is dry and firmly seated over the first-stage inlet before the regulator goes anywhere near water, because water inside the first stage is the leading cause of internal corrosion. Rinse in fresh water without pressing the purge button, since purging while depressurized can draw water back into the second stage. Shake out the water and hang it to dry with the hoses in wide, gentle loops rather than tight bends.

Regulators travel well and are usually best carried in hand luggage where they will not be crushed or lost. A regulator holds no gas of its own, so there is nothing inherently problematic about it on an aircraft, though the airline and security screeners always have the final say. Pack it dry with the dust cap in place, in a padded regulator bag or wrapped in soft gear.

Many modern regulators are supplied as suitable for nitrox mixes up to 40 percent oxygen, which is the widely used recreational industry standard, while anything above that requires dedicated oxygen-clean equipment and procedures. Confirm what your specific regulator's manual states, and follow your nitrox training and your fill station's requirements. Never assume a regulator is oxygen-service clean simply because it looks clean or is new.

A yoke (A-clamp) fitting clamps over the tank valve and is the most common connection across much of the recreational world, while a DIN fitting screws into the valve and is standard in much of Europe and in technical diving. DIN captures the o-ring inside the threads, which many divers consider more secure, but yoke is often what rental cylinders provide. Adapters exist in both directions, so check what is used where you dive before deciding.

The octopus is your backup second stage, carried so you can share air with a buddy who is out of gas, or breathe from it yourself if your primary fails or free-flows. It is normally on a longer, brightly colored hose so it is easy to find and hand over under stress. Secure it in the triangle between your chin and the bottom of your rib cage so it is instantly accessible and not dragging through sand or coral.

Store it fully dry, out of sunlight, with the dust cap in place and the hoses in wide loops rather than tightly coiled. Avoid hanging it by the second stages for long periods, which stresses the hose fittings; laying it flat in a padded bag or hanging it by the first stage is kinder. If it has sat unused for a long stretch, have it checked before your next trip rather than assuming it is ready to dive.

The yoke sealed version of the ST1 weighs 2.3 pounds, according to Atomic Aquatics' published specifications.

The ST1 is offered in gray, and Atomic Aquatics also offers an optional color kit for divers who want a different appearance.

AFC is Atomic Aquatics' patented Automatic Flow Control system built into the ST1's second stage, featuring a rapid adjustment knob. It works together with the pneumatically-balanced poppet design and high-flow case to let the diver fine-tune the second stage's breathing characteristics.

Yes, the ST1 uses the same titanium second stage components as the T3, paired with a solid 316 stainless steel first stage.