Ocean Reef GSM Dual Channel Communication Unit 33122 027690

Video: Ocean Reef Neptune Helmet with Communication Kit
Mfg Part #: 33122
  • Features a digital driver for vocal message equalization, an automatic system for activating (DAT) transmission and a double transceiver channel
  • The standard frequency (channel one) is the same for all units, so it is possible to talk directly with any other GSM DC, GSM DAT, GSM, M-101A receive units, surface M-105 Digital units and all previous surface systems (M103 - M104 - M105)
  • The double channel allows two different diver groups to operate in the same area, limiting the interference between them

Customer Reviews for Ocean Reef GSM Dual Channel Communication Unit:

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Average Customer Review: based on 2 reviews.

Rating: Awesome
Reviewer: Richard Belmore
Im a member of a Dive Team, we used the Communication units on a drowning recovery. The Units worked perfectly, we used them along with our surface unit to guide he divers through low vis conditions.

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528 out of 1056 people found this review helpful.

Rating: Comm Unit
Reviewer: James Athey  -  View all my reviews
I understand that these are quality comm units, but we had difficulties and decided to purchase a competitors model instead. James

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743 out of 1465 people found this review helpful.

Questions and Answers for Ocean Reef GSM Dual Channel Communication Unit:

  • Mark:

    It looks like this unit is mask or strap mounted? Does it include a microphone for FFM use?

    Darrick  (Certified Scuba Instructor at Scuba.com):

    Hello Mark, yes this comes with everything that you will need to talk to other divers or a surface unit if you have one of those. Also this unit will mount to the mask on the left side.

  • Dave:

    Could this communications unit be used by a dredge tender, in the water up to shoulders tending the dredge but tenders head not submerged, to communicate with an identical communications unit used by a diver who is working underwater?

    Darrick  (Certified Scuba Instructor at Scuba.com):

    Hello Dave, if you are trying to talk to the diver underwater you need this unit. Ocean Reef M100 Portable Surface Transceiver Unit web link: http://www.scuba.com/scuba-gear-168/029058/Ocean-Reef-M100-Portable-Surface-Transceiver-Unit.html. To talk to the diver underwater you need to have a transducer in the water to talk to him.

  • Kubilay:

    Thanks in advance for the answer. I am going out for speargun at weekends with my family. They stay at shore when I am 1-3 miles away. Sometimes I wonder if they are okay. (because they are alone there). I dive up to 60 foot. I want to communicate with them only when I am at surface( no need for underwater communication). What could be the solutions? thx again

    Bob  (Certified Scuba Instructor at Scuba.com):

    Unfortunately, this product won''t work. This is for in-water use and the user needs to be underneath the transducer for the most part in order to have communication with the surface. There may be other solutions. Please contact our instructors at info@scuba.com for information on alternate products.

  • Eddie:

    looking for high end underwater communications. is GPS an option ?

    Arthur  (Certified Scuba Instructor at Scuba.com):

    Hello, GPS doesn''t work underwater. So it''s definitely not an option.

  • Robert:

    I have two of these units but was never able to get them to work to where they were useful in recovery dives is there some place I can send them to be checked out thanks

    Darrick  (Certified Scuba Instructor at Scuba.com):

    Hello Robert, you can send them directly to the manufacture for warranty and non-warranty work. Here is the link: http://www.scuba.com/resources/repair/oceanreef.aspx. to all there contact information.


product code: 33122GSM DC

The GSM DC™ underwater transceiver unit incorporates the latest innovations in underwater ultrasonic 2-way radio communication. The unit features a digital driver for verbal message equalization, an automatic system for activating transmission (DAT™), and a double transceiver channel. The standard frequency (channel 1) is the same for all Neptune System units, so it is possible to communicate with any other GSM G.divers, GSM DC™, GSM G-Power, GSM G-Power SL, GSM CUBE3, M101A G.divers receive units and M105 Digital / M100 G.divers surface units. The GSM DC™ is a dual channel (DC) unit, which means it is equipped with two transceiver channels. By pressing buttons 'A' and 'B', it is possible to change the frequency channel. Any time the channel is changed, a recorded message informs the diver of which channel has been activated (channel 1 or channel 2). The two channels allow different diving groups to operate in the same area with limited interference and confusion. The GSM DC™ sound quality depends upon the D-Mic microphone, a special dynamic microphone with high acoustic qualities, and the microprocessor (DSP), which takes the digitized vocal message and filters out unwanted noise such as exhaust, air bubbles, and/or mask vibrations.

Wireless ultrasonic unit
DIGITAL driver for vocal message equalization
Automatic system for activating transmission (DAT)
Double transceiver channel
Automatically activated once submerged in water, receiving also automatic
System type H-SSB

Code - 33122

Type - Wireless ultrasonic

Activation - Automatic

Transmission - PTT

Receiving - Automatic

Speaker volume adjustmant - Yes

System type - H-SSB

Frequency - 32.768 kHz ch. 2 41.000 kHz

Working Range - 200m/600ft

Rated Depth - 40m/120ft

Powered by - 9v alkaline

Autonomy (total) - 9h

Low Battery Autonomy - 1h

Low Battery Alarm - 1 beep/30 sec under 7.5 v

DAT - Yes

Transmit receive cycle - Yes DAT mode-30 sec transmit 20 sec receive

Squelch - Automatic

Weight with batteries - 370g/12.9

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