As usual, things are not so simple in the last frontier. The challenges are numerous when it comes to installation and maintenance of remote sites necessary for the Rescue 21 radio network. The Coast Guard describes Digital Selective Calling and the currently deployed Rescue 21 sites on their project website, with a special mention for Alaska and the projected time to deployment.
The summary is that we can hope to have USCG monitoring of DSC calls over VHF sometime in 2017. It is still important to realize that even though the Coast Guard is not listening through their repeaters for DSC, many vessels do carry DSC capable VHF equipment. Any transmission using DSC over VHF would be heard by local area radios even without the shore installations the USCG is putting in.
Relying on nearby vessels to hear your DSC call is more helpful during the brief but busy summer months in Alaska, with increased recreational and commercial traffic. This is something to consider if you have little time, but know there is boat traffic nearby and need to get a distress call out via radio.
Sounds like a good plan, right? Chances are that one of those boats may likely have a DSC equipped radio since the technology has been available for 15 years, and required on all new VHF radios sold in the US since 1999 under an ITU standard SC-101 mandated by the FCC. That standard allowed for only one receiver in the radio to scan between channel 70 and the selected watch channel. It would then be possible to miss a DSC call on this type of radio.
Now, the current requirements for VHF radios sold or installed in the US must be DSC Class D. These radios have a dedicated receiver for channel 70. All DSC calls are transmitted on channel 70, so having a dedicated receiver means that there is no chance for a Class D user to miss a call. So, since March 25, 2011, all VHF radios sold as new have been Class D radios and those built to earlier RTCM 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.
The USCG offers another bit of advice on their Navigation Center website ...
The Coast Guard urges, in the strongest terms possible, that you take the time to interconnect your GPS and DSC-equipped radio. Doing so may save your life in a distress situation! Before interconnecting your radio & GPS consult the owner's manuals.
So verify your VHF radio system is up to the task by making sure you can also hear other boaters in distress through DSC. Taking the necessary steps now will ensure you will be able to not only hear others who may need assistance, but you will be able to instantly notify the Coast Guard when Rescue 21 is a reality in Alaska.