Maritime Mobile Service Identify (MMSI) is a mouthful. It’s also long – a nine-digit number that works like a phone number on your DSC-VHF radio to call for help. If you have it, all you have to do is push a red button on your VHF (even a child can do this) and the radio will automatically and immediately broadcast your boat’s location, in exact latitude and longitude, to all other boats with DSC-VHF radios within range. It also will show your boat’s location on their chart plotters and determine the distance and bearing back to your boat. But it…