Ask Sail: So Many Numbers

Dick Atherton, of Boston, Massachusetts, asks:

I recently purchased a used Hunter with VHF and SSB radios installed, both with MMSI numbers pre-memorized. To prepare for a bluewater cruise I am now installing an AIS transponder, and the technician has asked for another MMSI number. What should I do?

Gordon West replies:

To cruise in foreign waters you’ll need an FCC Ship Station License. You may not transfer your old FCC license (or your call sign) to your new boat. Nor can you use the MMSI number previously memorized in the VHF and SSB radios.

To obtain a Ship Station license, as well a Restricted Radiotelephone Operator permit (required for travel outside the U.S.), go to When your FCC license arrives, it will show a newly assigned MMSI number, which must be written into your VHF, SSB and AIS units. Find an NMEA master dealer (see in your area, and he or she can clear the MMSI memory in the radios and input your new number. 

Got a question for one of our experts? Send it to

Most Read on Sail

Also Popular on Sail


Leave a Reply