• Get connected! Every VHF radio should have DSC capability and be connected to its own or to the vessel's GPS.

• Get an MMSI number. The FCC has an online process for domestic and international use, including SSB. Boat US and Power Squadron may also act as intermediates in providing a more limited U.S. MMSI.
• The MMSI is, in effect, your VHF radio's "Telephone Number." It automatically provides information to the Coast Guard in an emergency situation. It will also identify your vessel for AIS purposes.
  
• Program your MMSI into your VHF radio carefully. Usually you get only one or two chances before the entries have to be cleared by a licensed technician.
• All aboard should know how to make an automated distress call - usually by lifting a small red cover and pressing the button beneath for about 5 seconds. Even that may be a lot to remember in a real emergency!
  

• Make proper test calls to avoid false alarms. New acronym: SYOM - See Your Operator's Manual.
  

• Program your radio with  MMSI's of cruising friends. SYOM.
• You will be able to select a name, choose a communication channel and hit "Go" or "X-mit" - SYOM.
• If your friend's radio is on - even if muted - it will sound a distinctive ring and advise your friend of your MMSI and your selected voice channel. They (may!) answer.
• The "Call" was selective. Only your friend's radio received the signal. The subsequent voice communication on the selected radio channel is, as always, heard by all monitoring that channel.
• Since Selective Calling is encoded on channel 70, calling channels 16 and 9 will become less congested over time
• Selective Calling was designed to be used on a daily basis for routine communications so that it will be familiar if needed to transmit or receive emergency calls.
  

Cruising friends, groups, regattas and sailing clubs can set up Group MMSI numbers. These are easily created by transposing digits of an existing MMSI. The range is that of VHF - about 20 miles. So a sailing club, even with several ongoing cruises, probably needs only one number. A group MMSI can also be used on DSC-SSB for offshore racing and cruising.

• Each club member programs the group's 9-digit MMSI with any chosen nickname into their radio. SYOM.
• A call to the group nickname "rings" all turned-on configured radios, including those on standby. The Selective Calling system will expand group reception by signaling radios which are not always monitoring calling channels.
• Go to the designated channel and participate in the group radio transmission.
• Use a selective group call to locate fellow club-members nearby, whether or not they are part of a formal cruise. 
• Try it in a harbor at low - 5W - output to locate club boats just out of "burgee range."

• AIS transmits a vessel's public MMSI information, along with vector data - location, course and speed - on VHF frequencies, usually sharing the masthead VHF antenna of a sailboat to maximize range. At a Class B max output of 5W the range is 5-10 miles.
• Icons of the transmitting vessels or AIS equipped aids to navigation are shown on dedicated or multi-function chartplotter displays aboard receiving vessels.
  
• The result is a valuable adjunct to radar, with the ability to "view" over land masses or built obstacles opaque to microwaves. HOWEVER: Keep the radar spinning, because the non-commercial or small vessel about to collide with you in the Muscle Ridge Channel fog may not have AIS equipment!
  
• Dedicated AIS devices are still the norm, although some recent high-end VHF radios are including AIS receivers or transceivers.
• Some VHF-AIS systems allow direct VHF calling by selecting AIS on-screen icons. SYOM! Or you can enter the displayed MMSI.
  
• You can recognize the boat names of fellow club cruisers with AIS-equipped boats from miles away and, from the distribution, identify cruise destinations and itinerary changes. Even initiate a group DSC call!