Ocean Reef Neptune III System
In stock — ships from Irvine, CA
Ocean Reef Neptune III System - YOKE / Black / ML (Medium Large) is backordered and will ship as soon as it is back in stock.
Pickup currently unavailable at 23D

The Neptune Space is available in two sizes, Small/Medium and Medium/Large.The sizing and measuring system were designed in accordance with the official measuring procedure used in the Los Alamos Scientific Laboratory Charts at the SBCCOM Mask Fit Facility-Aberdeen Proving Ground (Maryland, USA). Before purchasing a mask, the customer may use the calliper to take two simple face measurements. Using the Full Face Mask Size Recommendation Chart, he or she can evaluate the size category into which the measurements fall. There are three different size categories on the chart: Small/Medium, Both, & Medium/Large. If the measurements fall within the both category, then the diver should technically be able to wear either full face mask (M/L or S/M), and in that case should try on a mask to select the best fit. Please note that the chart boundaries fade. The fading areas represent less common face measurements. It is very likely that a mask will still fit comfortably even if measurements are located in these fading areas.
Ocean Reef Neptune III System - YOKE / Black / ML (Medium Large) is backordered and will ship as soon as it is back in stock.
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Product Information
Ocean Reef Neptune III System combines a Neptune III Full Face Mask IDM with rugged design for scuba diving, delivering comfort and safety in the water. The mask offers a panoramic field of view and a secure seal, optimized for varied diving conditions and a robust gear setup. It is built for durability in challenging environments and suits unisex, adult divers across multiple sizes and colors, with a first-stage option to support different air configurations.
The package includes everything needed to dive with confidence: a Neptune III Full Face Mask IDM with Backpack, a first stage, a standard hose, a QRS (Quick Removal System) doffing handle, and the Extender Kit with frame and accessories (frame already mounted).
- Neptune III Full Face Mask IDM included & Backpack
- First stage included
- 1 - standard hose
- QRS - Quick Removal System doffing handle
- The full Extender Kit (frame + accessories - frame is already mounted)
- Unisex, adult sizing
⚠️ WARNING: This product contains chemicals known to the State of California to cause cancer, birth defects, or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.
Frequently Asked Questions
Why dive with a full-face mask like the Ocean Reef Neptune III?
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.
What comes with the Ocean Reef Neptune III full-face mask?
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.
What size Ocean Reef Neptune III do I need?
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.
Is the Ocean Reef Neptune III certified and safe for cold water?
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.
How often does a scuba regulator need servicing?
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.
How do I rinse and care for a regulator after diving?
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.
Can I fly with a scuba regulator?
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.
Can I use my regulator with nitrox?
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.
What is the difference between DIN and yoke regulators?
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.
What is the octopus regulator for?
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.
How should I store a regulator between dive trips?
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.
How do you equalize your ears in an Ocean Reef Neptune III?
The Neptune III has a built-in 3D equalization device — you close your nostrils with it and equalize normally, without breaking the mask's seal or trying to get fingers inside the skirt. That is the single biggest practical worry divers have about full-face masks, and it is solved in the mask itself rather than with an accessory.
Can I breathe surface air with the Ocean Reef Neptune III without using my tank?
Yes — the mask includes a surface air valve that lets you breathe ambient air at the surface while the mask stays on your face, so you are not burning tank gas waiting on a boat or on a surface swim. It is standard equipment, included with the mask along with the backpack harness, quick-release doffing handle, standard hose, extender kit and multitool.
Can I add underwater communications to the Ocean Reef Neptune III?
Yes — that is one of the main reasons divers choose a full-face mask. Ocean Reef's GSM Mercury digital wireless communicator mounts to the mask's Extender Frame (which comes in the box with the Neptune III): push-to-talk transmit, continuous receive, two speakers at three volume levels, a range up to about 250 meters, a 40-meter depth rating and roughly 25 hours per charge. There is also a Dual Power version that runs one channel with a reduced-power mode for close-range use like training groups.





































