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Cell Phones vs. VHF Calling

DSC calling lets area boaters help rescue efforts.

The 411 on DSC

Boaters have preferred their personal cell phones to push-button VHF calling.

Capt. David McBride of the U.S. Coast Guard is chief of the U.S.C.G. Office for Search and Rescue. That makes him the guy to ask my heretical question: Why doesn’t the nation’s new and hugely expensive Rescue 21 system fully incorporate distress calls from mobile phones, like 911 on the water?

After all, I reason, most smartphones nowadays have a GPS built in, and BoatUS has already put the theory into practice. Last year the nationwide boating organization launched a smartphone app for members needing a tow. Press the “call for a tow now” button and TowBoatUS gets an immediate message with information about a vessel in trouble and its latitude and longitude before the dispatcher even answers the phone.

You could have a search-and-rescue app for smartphones that summoned help from the nearest Coast Guard unit with position data included. You could have cell-phone manufacturers include a *505 function (looks like SOS) on the phone for manual emergency calls. As far as hoaxes, you certainly would know who was making the call, or at least whose phone was being used.

McBride balks. He admits the U.S.C.G. policymakers have struggled with the idea, but cannot bring themselves to encourage the use of mobile phones as a rescue tool. For one thing, as many readers may have learned the hard way, “cell phones and water do not mix.”

“The Coast Guard continues to work with the industry to try and improve the existing 911 system especially with regard to streamlining the flow of accurate information to the responders,” McBride says. “Due to the complexity of geo-sorting and the infrastructure required to run a 911 system, it is not in the Coast Guard’s or taxpayer’s interest to attempt to recreate a redundant system just for the Coast Guard to use.”

My question is prompted by a new U.S.C.G. initiative to try to get recreational boaters to enable the so-called DSC feature on their VHF radios. Digital Selective Calling (DSC) requires boaters to register their VHF with the government and wire it to a GPS. At the press of a single button, DSC radio technology can put a Coast Guard rescue helicopter overhead within minutes, but in the 12 years since the government mandated this technology in VHF radios, only a small fraction of U.S. boaters do the two things necessary to enable it.

Another Coast Guard officer, Rear Admiral Robert Day, says nine out of ten DSC distress alerts have no position information because the radios are not connected to a GPS and six out of ten DSC calls have no Maritime Mobile Service Identity number (MMSI) registered to the radio of origin. (Registering a Maritime Mobile Service Identity is free and easy to do with the help of organizations such as BoatUS. Information provided at registration provides rescuers with a description of the vessel in distress, the owner’s name, and contacts).

“Despite the promises DSC technology offers in significantly reducing the alerting and search time for mariners in distress, there’s little a Coast Guard watchstander can do after receiving a distress alert with no position information, using an unregistered MMSI, and having no follow-up voice communications,” Day wrote in a letter to the National Marine Electronics Association. 

Day wants VHF and GPS manufacturers to adopt color-coding for the wires that need to be connected to let these two devices exchange information. He sees non-standardization as an impediment that should be eliminated. Many in the marine industry agree that GPS integration procedures are overly complicated, as is the registration process. One industry veteran, Erik Kunz of Furuno, describes the entire process as “clunky.”

Twelve years have passed since the government mandated that all VHF radios sold in the U.S. be DSC ready. For 12 years, the government and boating groups have pleaded with boaters to register and connect a few wires. As Coast Guard rescue stats suggest, only as few as one in ten VHF radios on the water are believed to be DSC enabled. 

Now, despite having spent $1.1 billion to modernize a lifesaving system for more than 40,000 miles of U.S. Coast, we are missing a key component. Rescue 21 designers had assumed a degree of cooperation from the boating public that has never happened. Although responders have superb radio-direction-finding capabilities to help pinpoint the source of a voice broadcast, nothing beats having the precise latitude and longitude of a sinking boat embedded in a DSC Mayday. 


The NMEA obliges the Coast Guard with a new color-coding standard, and one of its members goes a step further. Standard Horizon incorporates a GPS receiver into its newest fixed-mount radio, the GX1700 VHF, making wire colors moot. 

The Coast Guard has been talking about something like the GX1700 for a while, but they are met by skepticism from VHF manufacturers’ engineers, citing the technical hurdles to reliable GPS reception below decks. Over the past few years, however, as GPS receivers become more sensitive and compact, Standard Horizon begins to see solutions. Having already added GPS to a five-watt handheld, it now does the same for a 25-watt fixed mount radio. Other manufacturers are expected to do the same, but this, of course, does nothing for the non-enabled radios already on the waterways.

Meanwhile, other marine industry observers suggest that the registration component of DSC be done at the point of sale, thus relieving the boater of having to exert any effort whatsoever. The policy makes sense, but it still raises the question: Why is it so difficult to get the majority of boaters to do the sensible thing? 

And that brings us back to the beginning. The maritime policy groups that initiated the DSC concept never anticipated the proliferation of cell phones. Here’s a telling comparison: Of more than 23,000 rescue calls to the Coast Guard in 2010, only 263 are DSC. Most are VHF voice calls, but more than 7,000 distress calls are made by phone. That suggests that a growing minority of boaters consider the phone as their primary tool in an emergency.


Though campaigns to educate the boating public about the benefits of DSC have not produced good results in the past, the efforts will be renewed over the next two years through groups such as the Power Squadron and Coast Guard Auxiliary. Part of the challenge will be to convince boaters that VHF-DSC is superior to mobile phones in boating emergencies. The argument pits quality versus quantity.

No one can responsibly dispute that a DSC-enabled VHF radio is far better than a mobile phone for a Mayday. But what about quantity? Any given Sunday sees more mobile phones on the water than VHF radios⎯many more. Imagine five buddies fishing on a center console; that boat has five mobile phones on it. Reality check: Everyone over 12 years old has a phone, on land and sea.

It was Stalin who famously said (of pitting his numerous tanks against better-equipped enemies): “Quantity has a quality all of its own.” The same could be said about mobile phones on the water.

The Standard Horizon Explorer GPS GX1700

This article originally appeared in the May 2012 issue of Power & Motoryacht magazine.