Ocean Reef GSM Mercury
Ocean Reef GSM Mercury 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 GSM Mercury is backordered and will ship as soon as it is back in stock.
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Description
Description
For scuba divers, the Ocean Reef GSM Mercury consolidates four Ocean REEF units into one compact system. It delivers extended range for reliable communication, stereo sound through dual earphones, clearer audio with a double channel option, and a long battery life for extended diving sessions.
In terms of design, the GSM Mercury folds inside the mask for easy packing, features a rechargeable, replaceable battery with about 30 hours of autonomy, and charges via micro USB. Digital Activation Transmission (DAT) enables hands-free operation, and the unit remains compatible with prior Ocean REEF units and other brands on the same frequency. A robust PTT button, D-Mic 2.0 module, and the Blue Mic design improve clarity, while three-level volume control and a clear voice menu support straightforward operation in underwater environments. The system’s range can exceed 800 ft / 250 m under suitable conditions.
Features
Features
- Extended range for scuba and diving communications, compatible with prior Ocean REEF units and other brands on the same frequency.
- Stereo sound via dual earphones for clear audio in noisy underwater settings.
- Foldable mask integration folds inside the mask for compact packing and quick setup.
- Rechargeable battery with ~30 hours of autonomy; micro USB charging from any power source.
- Double channel option for separate teams or conversations; range up to 800 ft / 250 m.
- DAT hands-free transmission for convenient underwater communication.
- PTT button with a D-Mic 2.0 module that is replaceable and designed to minimize entanglement.
- Blue Mic design to enhance audio clarity; three-level volume control and a straightforward voice menu.
Payment & Security
Payment methods
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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
How does the Ocean Reef GSM Mercury underwater communication unit work?
The GSM Mercury is a digital wireless underwater voice communicator that mounts to an Ocean Reef full-face mask like the Neptune III (via the mask's Extender Frame). It uses push-to-talk to transmit and receives continuously, with two speakers at three volume levels and a hydrophobic microphone. Range is up to about 250 meters (800 feet), the unit is rated to 40 meters, and the rechargeable battery gives about 25 hours of use per charge via micro-USB.
What is the difference between the GSM Mercury and the GSM Mercury Dual Power?
They are the same communication unit with different channel setups. The standard GSM Mercury has two fixed frequency channels. The Dual Power version instead runs a single channel with two selectable power levels — normal power for full range, and a reduced-power mode intended for close-range use like training groups — and is identified by its Dual Power label. Both mount to and are optimized for Ocean Reef Neptune-series full-face masks.






