DSC, or Digital Selective Calling, "acts like the dial and bell of a telephone, allowing you to 'direct dial' and 'ring' other radios, or allow others to 'ring' you, without having to listen to a speaker," according to the U. S. Coast Guard's Navigation Center. Digital selective calling also, "allows mariners to instantly send an automatically formatted distress alert to the Coast Guard or other rescue authority anywhere in the world.
A DSC radio is required on all passenger and cargo vessels over 300 gross register tons. However, all VHF marine radios made after 17 June 1999 have DSC capability.
Change in Emergency Radio Procedures
Vessels relaying distress calls to the Coast Guard should be sure that the correct identity of the ship in distress is acknowledged, since the Coast Guard now treats mayday relays as individual distress calls.
DSC Should Be Interconnected With GPS
DSC must be connected to GPS on commercial vessels of 300 gross register tons or greater. On recreational vessels, the Coast Guard urges in the strongest terms possible, that you interconnect your GPS and DSC-equipped radio.
Article Written By Will Charpentier
Will Charpentier is a writer who specializes in boating and maritime subjects. A retired ship captain, Charpentier holds a doctorate in applied ocean science and engineering. He is also a certified marine technician and the author of a popular text on writing local history.