DSC VHF Handheld Radios

JohnAbercrombie

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Victoria, BC
More and more I hear recommendations for DSC VHF handheld radios because of the 'SOS' button which will 'squawk' a distress signal with the lat-lon (GPS) coordinates of the radio.
Ideally the radio will be powered on while paddling, I guess, but I tend to keep the radio off, thinking I am 'saving' the energy in the battery pack to use if I am in a real emergency situation.

So, what happens with a DSC radio in this scenario:
Radio is off.
I end up swimmng. I pull the radio out of my PFD.
I turn on the radio and push the DSC SOS button.
I'm swimming with the radio tethered to me, trying to hold on to the boat and paddle and radio.

Does the radio squawk a DSC SOS right away?
What GPS co-ordinates does it transmit?The ones from the last time it was powered up, or none, until it gets GPS satellite signals and calculates a position?
How long does it take a DSC radio to calculate a GPS position from the time it is turned on?
Where is the GPS antenna? Does the radio 'face' have to be pointed at the sky? That's difficult; most folks grab a VHF to point the VHF antenna vertical.
In the water, in rough conditions with a kayak beside my head doesn't sound like a ideal spot to get good GPS signals.
Are there many documented cases of kayaker rescues using DSC VHFs?

Thanks!
 

cougarmeat

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John, many of the reasons you mention above - and my experience using at least 8 different GPS units over the years - is why I focus on the EPIRB,Spot/InReach/Zoleo (i.e. Satellite) type solutions. I carry a Marine VHF for the weather reports. And there are times when it would be useful for person-to-person communication. For the person with a ham radio VHF unit, Vancouver Island - at least on the east side, also has an array of ham radio repeaters all along the coast. And there are regular "nets" one can check into, letting others know your location and intended next location. The deal is, gear-wise, the Marine VHF is okay in the Marine environment but it won't help you much on Mt Adams. The Satellite devices are a "Don't leave home without it." (when solo) item for any occasion.

News Item: Our local library now has HotSpots they can lend out like a library book. You can check it out for 3 weeks at a time. The HotSpot connects to some cellular service (maybe more than one) and via the "data plan", it provides a WiFi connection. This is useful because some chart/map software - like Gaia - have a (near) real-time radar/weather option. But it's only useful if you can access the internet. Away from any StarBucks (they don't have one on Patos Island yet) or Safeway store, etc., you'd need a cellular connection with a data plan to get updates. My iPad Mini doesn't have a cellular option. So that HotSpot provides that connection.

Note that you can make most phones "hotspots" via preference settings. But in that case, whomever you will be sharing it with will be using your dataplan while surfing the web with a laptop. In the above case, the library foots the bill for whatever contract they have with the cellular carrier/s.
 

Peter-CKM

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Dec 1, 2011
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San Francisco, CA
Interesting question, and I don't know the answer to it. I suspect it either won't send it or will delay sending it until it has a GPS fix. Or maybe when you hit the SOS button, it sends out continuously at intervals, so it will send a message without coordinates until it gets a fix. Unless someone here has an answer, might be something you will need to go to a manufacturer to get an answer from.

If you use a SPOT (or similar) or PLB the same way (kept off to save power), you will have the same issue. Added to that, there will also be a delay as the device tries to find a satellite, the service that receives the satellite message tries to figure out who/what is going on and who to call, and makes the call. Even if the device is on and it has a GPS fix, I've heard numbers from 30 minutes to 2 hours from when a button is pushed until when an actual call for help is received by the emergency folks who will actual come out.. So if you are in areas where VHFs are reasonably reliable, the DSC option likely is your faster safety solution (even if you have to turn on and wait for it to say it has signal before hitting the 911 buttton).

This from a guy who has a PLB and non-DSC VHFs. As cougarmeat mentioned, the satellite based devices have the advantage of being usable outside of VHF range an even outside of boating environments.
 

JohnAbercrombie

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Since the DSC 'red button' is often compared to satellite devices:
This is a good overview of the differences between a PLB and a Satellite Communicator like a SPOT/Zoleo/InReach.
 
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cougarmeat

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In the "It pays to do your research" department ... at one time, maybe still, the West Marine VHF radio was just a Uniden radio rebranded. I had some grief with mine (and returned it) because though the communications channels are standard across radios (same frequency for channel 68 for example), there is no such requirement for the weather channels (or West Marine/Uniden chose to ignore it). As such, a station you could hear on channel 4 of a Horzion Radio might be channel 7 on the West Marine radio. So a buddy is listening to the weather on Channel 4 of his Horizon radio and I turned my West Marine radio to Channel 4 and couldn't hear a thing - because that same station/frequency was WX channel 7 on the West Marine. I thought the radio was malfunctioning because I couldn't hear anything on channel 4.

That was years ago and since then I move to Horizon. Maybe West Marine/Uniden learned their lesson and now all Marine Radios use the same channel designations for the WX broadcasts.
 

JKA

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Banks Peninsula, New Zealand
I've attached an article I wrote on a rescue of a paddler in 2014.

Long story short: Paddler stuck offshore at night, triggered Spot, found by helicopter, rescued by fishing boat.

Input from the paddler, the helo crew and the fishing boat skipper.

The article highlights the limitations of Spot as a rescue beacon. Note that this happened in 2014, the tech has probably improved.

 

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JohnAbercrombie

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Thanks, @JKA - excellent report, with some important lessons in it.
It points out the advantages of the PLB with the 121MHz homing signal over the SPOT .
Also, it emphasizes the need for tethers on safety gear which can easily slip from wet hands, or be dropped when the paddle needs to be gripped.

It seems that there was a 30 (?) minute delay before the SPOT organization contacted the NZ rescue services, and then another hour to get the rescue helicopter in the air.
It's a good thing that the paddler was fit and still paddling. If he'd been in the water he wouldn't have survived.

I've been remiss in not thinking more about night-time visibility to potential rescuers.
"I never paddle at night; why bother with reflective patches on my boat or lights?"
I'm going to change that.
 

JKA

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Jul 25, 2016
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Banks Peninsula, New Zealand
@JKA - Are DSC VHF radios in common use in NZ?
I wasn't sure so went Googling:


"WARNING: some marine radios are equipped with a VHF DSC facility. DSC signals from these radios are not processed by the New Zealand Maritime Radio network. Other, similarly equipped, radios within VHF range may be able to receive and interpret these signals but this cannot be guaranteed. In New Zealand coastal waters, voice must be used for distress and urgency messages."

So I guess: No.
 

alexsidles

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Jan 10, 2009
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Seattle WA
The article highlights the limitations of Spot as a rescue beacon. Note that this happened in 2014, the tech has probably improved.
According to its website, the International Emergency Response Center was acquired by Garmin in 2020.

Have you ever dealt with Garmin customer service, or read a Garmin user manual? Are these really the people you want trying to figure out what kind of rescue you need? :)

Alex
 
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