This page contains information about safety bulletins or important notices about marine electronics.

Concerning Mounted VHF Radios:

            "It has come to the Coast Guard's attention that an automatic channel switching feature found on certain models of Digital Selective Calling (DSC) equipped VHF marine radios may create an unintended hazard by automatically switching from a working channel that might be in use at the time to Channel 16 when the VHF marine radio receives a DSC distress alert, distress alert acknowledgment or other DSC call where a VHF channel number has been designated.  This could happen without a vessel/radio operator's immediate knowledge and could initiate and unsafe condition by which the vessel/radio operators would believe they were communicating on a working channel such as Channel 13 when, in fact, they were actually on Channel 16.  Imagine a towboat operator on  the lower MIssissippi River making a passing agreements on VHF channel 67 and then suddenly, without warning, not being able to quickly reestabalish communications with those vessels because hi/her radio automatically switched to Channel 16 instead.

Since this unsafe condition can happen at any time, the Coast Guard strongly recommends disabling the automatic channel switching feature when maintaining a listening watch or communication on the designated bridge-to-bridge radiotelephone, or while monitoring the vessel traffic services (WTS) channel.  Radios that lack the disabling feature should not be used for bridge-to-bridge or VTS communications.

The International Telecommunications Union Sector for Radiocommunications, Reccomendation M.493-11 published in 2004 and later versions require DSC-equipped radios to provide for disabling of this channel auto-switch feature.  In the United States, the Federal Communications Commission (FCC) requires all DSC-equipped radios certified after March 25, 2009 to meet this requirement.  Manufacturers that do not provide a disable function are not encouraged to do so and to inform their customers if means for corrrection exist.

The Coast Guard strongly reminds radio operators and other users to always ensure they are on the proper operating channel when communication or maintaining watch, particularly with DSC-equipped radios capable of channel auto-switching.

This safety alert is provided for information purposes only and does not relieve any domestic or internation safety, operations or material requirement.  Developed by the Spectrum Management and Telecommunications policy division (CG-652), United States Coast Guard Headquarters, Washington, DC.  Questions should be directed to MR. Russell Levin at (202) 475-3555 or Russell.S.Levin@usgc.mil."

" DSC-Equipped Marine Radios Must Meet More Rigorous Technical Standards Beginning March 25, 2011

Beginning on March 25, 2011, the Federal Communications Commission will prohibit the manufacture, importation, sale and installation of fixed mounted (non-portable) digital selective calling (DSC) equipped marine radios that do not meet the requirements of International Telecommunications Union (ITU-R) Recommendation M.493-11 or higher, and in the case of  Class D VHF DSC equipment only, International Electrotechnical Commission (IEC) International Standard SC-101 can no longer be manufactured, imported, sold or installed; however, previously-installed radios meeting the older standard may continue to be used.

On March 25, 2012 the FCC will not accept new applications (but will continue to process then-pending applications) for certification of handheld, portable DSC-equipped radios that do not meet the requirements of ITU-R Recommendations M.493-11 or higher and IEC 62238.  On March 25, 2015 the FCC will prohibit the manufacture, importation, and sale of portable DSC-equipped radios that do not comply with these standards.

Compliance with these new international technical standard ensure DSC-equipped radios wil incorporate many new safety features and functions, including eliminating dangers associated with automatic channel switching addressed in Coast Guard Saftey Alert 02-10 of April 13, 2010.  New features also include provisions for making test calls, dual receiver funtionality to improce operation,  and Global Posotioning System (GPS) interconnection alarms designed to ensure that distress alerts include a valid and accurate position.  The new requirements ensure improved detection of distress alerts, a reduction in the rate of false alarms, and reduced incessant alarming caused by DSC-equipped radios meeting the older standard.

The FCC with the support of the U.S. Coast Guard adoped final rules, effective January 25, 2008, implementing these new more rigorous standards.  The FCC stopped accepting new applications for certifications of DSC-equipped fixed mounted radios not meeting the new ITU-R and IEC standards on March 25, 2009.  (47 CFR 80.225)"