Got this great reply from Mark Lane at Oceanic:
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To set the transmitter ID code on your VT3 wrist unit, press and hold the left (mode) button until the computer is in NORM mode. Once in NORM, simultaneously press and hold the right (advance) and side buttons until you see SET U on the screen. Once in SET U, use the right (advance) button to advance through the screens until you see the TMT1 screen. This is where you enter your transmitter ID code. To do this, first make sure the ON/OFF toggle is set to ON by using the side button. Once the unit is toggled to ON, press the right (advance) button to move the cursor through the digits displayed at the bottom of the screen. When you reach a digit that needs to be changed, you can make the change using the side button. Once the change has been made, use the right (advance) button to save the change and move to the next digit. Continue in this manner until all six digits correspond to the transmitter ID code stamped on the body of your transmitter.
This process is described on pages 50-51 of the VT3 Operating Manual, which can be downloaded from our website at
Oceanic Worldwide - Owner Services - Owner's Manuals. If you have any other questions, just let me know.
Regards,
Mark Lane
Technical Support Specialist
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Clear and simple help within a couple of hours of sending them an email, awesome customer support, thanks to Oceanic and Mark Lane!