In the era of mobile telephones, underwater communication represents an essential evolution not only for safety, but also to improve and widen the operating conditions. To communicate means to exchange information and emotions in real time. It means to make the dive easier, more comfortable and amusing. It means to open new horizons to the underwater activity. If you lose sight of your dive buddies or the boat, you are completely isolated, unless you have an appropriate transceiver. Ocean REEF proposes an underwater communication standard, which is solid, sturdy, and easy to use for recreational diving, research, training, commercial or scientific use.
The GSM DAT (code 33116) communication system incorporates the latest innovation in underwater ultrasonic 2-Way Radio communication; featuring a digital driver for vocal message equalization and an automatic system for activating (DAT) transmission. The GSM DAT can be used on the Neptune II Full Face Mask, preferred, or on other Full Face Masks fitted with a standard DIN female connection. Underwater communication technology is accomplished with ultrasound and is started by a PTT, Push to Talk, microphone button, which must be pressed to activate transmission and released to receive.
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 one 32.768 kHz or channel two 41.000 kHz). 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.
The D-Mic housing has a hydro phonic membrane, which is permeable to air, but prevents water from passing through into the electronics. The membrane limits attenuation of the vocal signals thanks to its reduced thickness. The permeable characteristics of the membrane keep the internal pressure equalized at the same level as the external ambient pressure so that the microphone can practically be used at any depth. The unit automatically activates upon contact with the water. The GSM DC uses a 9V alkaline battery and has a low battery alarm which beeps every 30 seconds when the battery is low (1-hour runtime remaining). The GSM DC unit's total battery life is approximately 9 hours and is depth rated for 120' (40 meters) with an operational range of 600' (200 meters). Product comes with an owner's manual and is covered by a 24 month limited warranty.