Ocean Reef Neptune III 2nd Stage Regulator

A full-face mask integrates the second stage regulator into the mask, so there is no mouthpiece to bite and no regulator to lose — you breathe naturally through your nose and mouth, which many divers find far more comfortable and less fatiguing, especially on long or cold dives. The six-strap harness holds it securely, the field of view is wide, and because your mouth is free, the mask is ready for underwater communication systems. It is popular for cold water, public safety, and any diver who wants a more relaxed breathing experience.

The Neptune III includes the mask with its integrated second stage, the backpack (six-strap harness assembly), a one-hand quick-release doffing handle, a surface air valve that lets you breathe ambient air at the surface without wasting tank gas, the standard hose, an extender kit (the accessory frame used to mount cameras, lights, or a communication unit), and a multitool for adjustments. You supply your own first stage, or step up to the Neptune III Package, which adds a first stage, octopus, gauge, and backup mask.

The Neptune III comes in two sizes, measured by the distance from the bridge of your nose to the bottom of your chin: Small/Medium fits roughly 10–11.5 cm (smaller faces, many women, and children 12 and up), and Medium/Large fits above 11.5 cm. The right fit leaves no gap between your chin and the silicone skirt. If you are unsure, measure nose-bridge to chin and send us the number and we will confirm the size.

Yes — the Neptune III is CE marked as Category III PPE, compliant with the EN 250:2014 diving standard, cold-water rated for use below 10°C, and tested to 61 meters. A patented internal air-circulation system keeps the lens from fogging and continually flushes exhaled air to minimize CO2 buildup, and a built-in 3D equalization device lets you close your nostrils to equalize without breaking the mask seal. It is a properly certified full-face system, not a surface snorkel mask.

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.

They are the same product. Ocean Reef markets this standalone, fully pre-assembled Neptune III second stage under the name Swap Regulator, SKU OR005091. It is the identical vertical, body balanced regulator that Ocean Reef integrates into the Neptune III full face mask, sold on its own so a Neptune III owner can keep a spare unit or swap the second stage quickly.

No. Ocean Reef requires that this regulator be installed by an Ocean Reef Authorized Service Center, or by an authorized dealer that has a Level 1 Service Technician on staff. The regulator arrives fully pre-assembled, but installation onto the Neptune III mask must be performed by that authorized service center or technician.

Yes, that is one of its stated purposes. Ocean Reef offers this pre-assembled unit as the upgrade path for Neptune III owners whose mask was certified only to EN250:2014 A>10 degrees C. The Swap Regulator carries EN250:2014 A<10 degrees C cold water certification, so installing it through an authorized service center brings the mask up to the cold water standard.

No. Ocean Reef lists compatibility with the Neptune III IDM (Integrated Diving Mask) only. It is a component for that specific mask system rather than a universal second stage. If you are unsure which Ocean Reef IDM generation you own, call 888-701-4017 before ordering.