Mariners and boaters alike may have noticed a distinct feature on newer marine VHF radios over the past few years – the presence of a red button on the front of the unit with a “DISTRESS” label on it.
This button is an indication that the radio is equipped for Digital Selective Calling (DSC). When registered to the user/vessel, and plugged into a GPS unit, this button allows the mariner to send an electronic burst transmission over VHF Channel 70 that can be received by the US Coast Guard and any other vessel with a DSC radio.
Transmitted instantly within the signal are the name of your vessel, your GPS position, and other information important to the Coast Guard or anyone coming to your aid. Also, the signal is automatically relayed from receiving vessels towards the shore – theoretically adding considerable distance to the range of your marine VHF radio.
Another benefit of the DISTRESS feature of DSC radios is the speed in which you can broadcast a MAYDAY. On Saturday May 1, 2010, the F/V Sea Clipper was suddenly pulled violently on her side. The crew did a fantastic job by managing to broadcast a MAYDAY and send a position via the VHF radio, but it is not too difficult to envision a similar scenario where there may have only been time enough to press that DISTRESS button.
Just as important as registering your emergency position-indicating radio beacons (EPIRBs), if you decide to get a DSC radio, be sure to register for your MMSI number. This is your “caller ID” for your vessel and VHF radio. Also, if you purchase a DSC radio, or already own one, be sure to connect it to your GPS unit so that the unit will be able to transmit your precise GPS location to receiving units and the Coast Guard. This position information has the ability to “take the search out of search and rescue” and can be the difference between having Coast Guard assets directly overhead versus searching a large area of ocean for your vessel. As a helicopter pilot, I cannot stress the importance of having a good datum for a search and rescue case.
As a sailboat owner and licensed merchant mariner, I know that a VHF radio, properly mounted and maintained, will provide for decades of reliable service and that replacing something that works perfectly fine is not always at the top of a priority list. However, with the advent of DSC technology, it might be a good time to upgrade “old reliable” with a more modern unit with state-of-the-art features including DSC. Spending money is not always fun, but buying a cool new electronic gizmo for your boat is always fun!
Check out the following web links to information on DSC radios:
• Boat US (One of the USCG’s industry partners in DSC): http://www.boatus.com/mmsi/
• Excellent Coast Guard Auxiliary Video: http://vimeo.com/6539272
• A Coast Guard Powerpoint presentation on DSC: http://www.uscg.mil/hq/cg5/cg534/SARfactsInfo /DSC_MMSIpresentationAug08.ppt