Ask Capt Gary
There’s nothing that drives me crazier than listen to people who apparently
haven’t a clue use their boat’s VHF for everything but what it was meant for— this includes babysitting; I simply love hearing a drooler jamming up Channel 16. There is protocol to follow when using your VHF and it behooves you to know it … especially should you ever be in an emergency situation. Here’re the high points. Range and Channel Use VHF radios operate on a line-of-sight basis; i.e., the top of your antenna has to “see” the top of a receiving antenna (here’s a line-of-sight calculator: www.qsl.net/kd4sai/distance.html). Theoretically. Radio waves do bounce off of things, so that explains why you may occasionally hear calls from, say, Barnegat Bay while you’re striper fishing The Race. That said, the transmission of a VHF signal is a function of the height of your antenna, the power output, the curvature of the earth and the height of the receiving antenna. There’s actually a formula for line-of-sight, and it’s the square root of 1.5 times the height of the antenna off the water; that will give you an approximation of your maximum transmission range. VHF channels are reserved for specific duties; go to www.navcen.uscg.gov/?pageName=mtvhf for a complete list. Over Ain’t Out and Vice Versa “Over” means “It’s your turn to speak;” an invite in order that both operators don’t speak at the same time. “Out” means you’re done, finished and will not transmit anymore. Ergo “Over and Out” are oxymorons (or something like that). “Over and out” means I’m waiting for your reply … but I’m not here! Channels 9 & 16 Channel 16 is meant for safety-concerned transmissions and initial contact transmissions only. Make it brief: “Old School, Old School, Irish G’bye.” That’s me trying to contact my buddy. If he replies “Irish G’bye, Old School,” you reply with: “Old School, Irish G’bye, 68,” meaning switch to 68 (or whatever channel reserved for ship-to-ship) to continue your chat. Keep it as brief as possible. And if your buddy doesn’t answer after three tries, wait at least 15 minutes before trying again. I checked with the US Coast Guard Navigation Center (NAVCEN) on the Channel 9/16 confusion. Channel 9 was set up to take some of the load off of Channel 16 when it comes to initial contact transmissions. With many of today’s radios able to monitor two and three channels at a time, setting up your radio to monitor 9 as well as 16 (you’re supposed to monitor 16 if you have a VHF aboard and aren’t communicating with someone on another channel) is the way to go. Spreading the word about Channel 9 to your fellow boater friends also won’t hurt. Monitor both channels and you won’t miss your buddy’s call. Safety Alerts There are three tiers of the alert transmission you need to know: Mayday, Pan-Pan and Securite. “Mayday” is for when it has all hit the fan. “Pan-Pan” (pronounced Pahn-pahn) is when you, your boat or a passenger need assistance, but nothing life-threatening is going on. “Securite” (pronounced Suh-cure-a-tay) is an announcement that there’s something going on that may affect you and your boat. There’s a format to follow when transmitting any of the alerts. Repeat the classification three times (“Mayday, Mayday, Mayday”). Give the name of your boat and the location: either by referencing a landmark or giving a GPS location. Then the nature of the problem, how many people on board, whether anyone is injured, and a description of your boat. Repeat all this at least three times (i.e., you’re saying Mayday nine times) if at all possible. Why? Because if someone heard you, they didn’t have time to jot down the transmission essentials the first two times you said it! DSC/MMSI DSC/MMSI is a one-red-button transmit feature that does all the work of a Mayday. It does need to be hooked to your GPS to provide location. Hold it down for three-to five seconds, and all the info is transmitted. You can pre-select the type of distress, or it goes out as “undesignated.” If your DSC alarm goes off, that means someone is in trouble, and it’ll note the location on your display. You can send Pan-Pan and Securite calls with DSC as well. Press the call or DSC button once, select “Urgency” from a pull-down menu, press enter. Ditto with Securite only push “safety” from the pull-down. You can also use the DSC feature to speak t
o someone privately. This is a neat feature for the fisherman who wants to turn a buddy — a really close buddy, apparently — onto a hot fishing spot. All you need is a Class D DSC radio. This has features allowing you to enter someone’ else’s MMSI and speak to them over it; you need the MMSI of the other boat to do this. An MMSI (Marine Mobile Service Identity) is a specific number assigned to your radio, which is logged with the US Coast Guard for search and rescue. You can get an MMSI from the Coast Guard (hwww.navcen.uscg.gov/?pageName=mtMmsi), BoatUS: www.boatus.com/mmsi/; the U.S. Power Squadron: www.usps.org/php/mmsi/home.php (click the LogIn/Register button); or Sea Tow; www.seatow.com/boating-safety/mmsi/register. Radio Checks Radio checks are worthless if they don’t come with a location. “Five-by-five,” “loud and clear,” or “Lima Charlie” all mean the answering station can hear you, but if they tell you their location (and they will if you give yours!), it’ll give you an idea of range. Sea Tow has pretty much solved the radio check problem by offering an automated system. You call on a specific channel (www.seatow.com/boating-safety/automated-radio-checks) and you’ll hear what you sound like at the receiving station played back to you. Out.