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Q&A DSC Alerts

What should I do if I accidentally trigger a digital selective calling alert?

A boater who initiates an unnecessary search, even accidentally, potentially faces civil and criminal penalties, fines and reimbursement of search costs.

On Sept. 4, the Coast Guard Sector New York Command Center received a DSC alert. The only information transmitted was the Maritime Mobile Service Identity, or MMSI. The center developed a search area based on a probable location and established a search pattern. It also researched the MMSI data and got in touch with the registered owner, who had sold the boat four years earlier. The center then contacted the second owner, who had sold the boat a week earlier. The Coast Guard eventually reached the current owner, who had inadvertently triggered the DSC alert while checking equipment.

No search was launched, but when Coast Guard aircraft and boats engage in a search that a false alarm triggers they’re not available for a true emergency. If you accidentally trigger a distress alert with DSC, take the following steps:
• Reset the equipment immediately.
• Tune for radiotelephony on the associated distress and safety frequency in each band in which a false distress alert was transmitted.
• Transmit a broadcast message on VHF channel 16 to “all stations,” giving the boat’s name, call sign, the time the alert was transmitted and the MMSI, and cancel the false alert on the distress and safety frequency in each band in which the alert was transmitted.
Boaters who own a DSC-equipped radio need to know how to use it. The first step is to register the MMSI data. Numerous websites, including BoatUS (, Sea Tow ( and the U.S. Power Squadrons (, enable owners to do this. Remember, if you’re not the first owner of the radio, MMSI data must be updated. A guide to proper use can be found at the Coast Guard Navigation Center at

This article originally appeared in the January 2012 issue.