Ocean Reef GSM Mercury, Owner'S Manual & Installation Manual

Mercury communication unit manual rel.1.2

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The GSM Mercury uses a dynamic microphone, ”Blue-Mic” encapsulated  and protected by a hydrophobic 
membrane.
The Blue-MIC is assembled to be less invasive and delicate than any other underwater microphone.
It is still possible to detach and replace by using two screws. 
The microphone allows dependable clear reproduction of the human voice.  It removes unnecessary 

noise such as the noise of bubbles being exhaled from the mask.

Its design is very similar to the D-Mic but allows a better audio clarity.
 
The Blue-Mic microphone uses a hydrophobic membrane that allows air to pass through while protecting 

the  microphone  from  water.  This  membrane  also  reduces  the  “muffling”  effect  allowing  a  phonic 

performance that is very high. Another characteristic of the hydrophobic membrane is its mechanical 

strength.  The Blue-Mic is fitted with a membrane that is designed to handle pressure of more than 
1bar (14.7 PSI). If the membrane brakes, the microphone will flood causing transmission to stop. 

OCEANREEF IDMs masks are designed to operate with “balanced” pressure. If the mask is removed 

underwater the microphone WILL NOT suffer any damage. However, continuing to descend WITHOUT 

the mask sealed on the face, the microphone may result in exceeding the 1 bar mechanical resistance 
of the membrane, so damaging permantly the microphone (in relation to the depth at which the mask 
is removed). Ascending must be done in accordance with the dive tables or dive computer to avoid 

decompression problems. 

The communicator and microphone should be rinsed with fresh water (immersed, high pressure water 
is not reccomended as it can damage components) after each dive and should be placed in a well 

ventilated area that is not exposed to direct sunlight to dry.
Blue-Mic does not have a polarity restriction when assembled on the PTT contacts. Be careful to 
unscrew the two screws before removing it.
Clean the microphone contacts and lubricate them on a timely base.

BLUE-MIC Microphone