Ocean Reef Neptune III Full-Face Diving Mask ID250 (Limited Edition)

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 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.

Hold the mask against your face without using the strap, look slightly down, and inhale gently through your nose; a well-fitting mask holds itself in place for a few seconds. Check that the skirt seals all the way around without digging into the nose bridge, and that there are no gaps at the temples or above the upper lip. A mustache can break the seal even on an otherwise well-fitting mask.

New masks carry a residue on the inside of the lens left over from manufacturing, and defog cannot stick to it, so the mask fogs until that film is removed. The standard pre-treatment is to scrub the inside of the lens with a mild abrasive cleaner or a dedicated mask prep and rinse thoroughly, repeating if it still fogs. Follow the mask manufacturer's instructions, particularly on coated or mirrored lenses.

Apply defog to a dry lens before the dive, spread it over the whole inner surface, then rinse briefly with water just before you put the mask on. Fogging happens when warm moist air meets a cooler lens, so a clean lens with a thin surfactant film is the fix. Keep sunscreen off your fingers before handling the inside of the lens, because that film fogs badly and is hard to remove.

Dive mask lenses should be tempered safety glass because it resists scratching and, if it ever does break, fractures into blunt granules rather than sharp shards next to your eyes. Untempered or plastic lenses scratch easily and can craze, which is why tempered glass is standard on scuba masks. Look for the tempered marking etched on the lens.

Yes, prescription options are widely available, usually as masks fitted with stock corrective lenses in set diopter steps, custom-ground lenses installed in compatible frames, or bonded lenses added to an existing lens. Not every mask frame accepts replacement lenses, so check compatibility before you buy the frame. An optician or a dive shop can help translate your glasses prescription into a mask lens choice.

Rinse it in fresh water after each dive day and let it dry away from direct sunlight, avoiding anything abrasive on the treated inner lens. Store it in a rigid mask box so the skirt is never compressed or creased, since a set crease in the skirt is a permanent leak. Keep silicone skirts away from petroleum products and prolonged UV, both of which yellow and harden them.

Not tight at all in the usual sense, because over-tightening is the most common cause of both leaks and headaches; a hard-pulled strap distorts the skirt and lifts the seal off your face. The strap should sit high on the back of your head and be just firm enough to keep the mask from shifting. If you need it cranked down to stop a leak, the mask does not fit your face.

The ID250 is a limited release of only 250 individually numbered pieces, created to mark 250 years of American independence and offered only in the USA. The ID250 is built on the Neptune III full-face platform and adds limited-edition numbering and American-heritage artwork.

This is the Mask configuration, meaning the full-face diving mask with the integrated second stage regulator, backpack, doffing handle, surface air valve, standard hose, extender kit and multitool. Ocean Reef also builds the ID250 as a System (mask plus first stage) and as a Package (mask plus octopus, traditional mask and quick-release disconnection). Contact us if you want help pairing it with a first stage.

Yes. A surface air valve lets you breathe ambient air at the surface without taking the mask off. Underwater, the integrated second stage supplies air while a one-way circulation system keeps exhaled CO2 from mixing with the fresh air feed and helps limit fogging.

The Neptune III design supports headset integration for dive communications, which is one reason divers choose a full-face mask over a standard mask and regulator. The full-face design leaves the mouth free and supports headset integration for underwater communication. Call 888-701-4017 and we will confirm the specific comms unit you have in mind before you order.