Personal Locator Beacons…

[Greg Mihalik]

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[Will Webster]

"I think you're completely missing the idea of the SPOT usage model. The whole idea of these messages is to leave an electronic history of your journey – so that your loved ones know where you are and so that SAR knows where to start. The SPOT usage model is totally superior to the standard PLB model where nobody knows where you are until you activate the device."

Tracking is an option with the Spot – or the Inreach – but plenty of us don't see value in it. I bought a Spot so I could let the folks at home know I was OK. Posting every bit of trail I take seems silly to me, but after my Mother-in-law was ready to call out SAR because it got down to 20F on a weekend outing we realized we needed a way to calm her down. It worked fine until the trip where nothing went out for 4 days, meaning that it caused more anxiety than if I hadn't bought it in the first place. Now we're probably going to buy an Inreach, so we will know whether the messages we send are actually going out.

The whole idea of a communicator as opposed to a PLB is that your loved ones at home know that as of noon today (or whenever) you were fine, not pinned under a rock / being digested by a bear / too hypothermic to move, or otherwise incapable of triggering a device. The breadcrumb option is a bonus for those who see value in it, but not central to the concept.

[Bob Gross]

"I will totally diagree that all GPS receivers suffer the same under a heavy canopy, that's just not the case."

Yes, I started into the GPS business in 1994, so I have seen many generations of GPS receivers, and I have seen huge variations in performance. Lots of the difference is based on the software nuances. However, lots of the difference is in the antenna design. Some users don't even know where the antenna is located within their receiver case, so they don't know where not to place a finger or a hand. If you really want to pull in a good signal, use an external antenna. Those are powered by the receiver, so you don't get something for nothing.

I have yet to see any brand of GPS receiver that will out-perform Garmin. I own three for my personal use.

–B.G.–

[Nick Gatel]

My first GPS was a Magellan purchased in 1998. The antena was visible as it stuck out the top. And it worked poorly under canopy. I have been doubtful ever since. My wife bought me a Garmin a few years ago, and I take with us on day hikes — makes her feel she bought something useful. I also noticed that some of the Garmin maps show old trails no longer found on other maps to include USGS. This feature makes for some interesting and exciting hikes, where we are almost guaranteed to have the hike to ourselves. Sometimes I take the GPS on winter trips where I expect storms to create poor visibility. But unlike most, the GPS is the backup, not the map and compass.

When it comes to electronics, I adhere and believe in Murphy's Law.

[Mike W]

Bob – I agree with you about the antennae and software being the key. The signals that any GPS receiver pulls in from the satellites is weak at best. It's all about how the software interpolates the mess it receives that makes the difference between good and bad units.

I thought you'd find it interesting (and any other GPS geeks out there)… the inReach SE user manual says:

"Antenna – Keep the satellite communicator antenna pointing up toward the sky and the face of the device pointing away from your body."

Not what I'd call the best design… you have to face the screen "away" from yourself to get the strongest signal. Kind of counter intuative. :)

[David Thomas]

>"Tracking is an option with the Spot – or the Inreach – but plenty of us don't see value in it. "

Will: I'm not a fan of SPOT, but I can see the value in tracking. Stuff can happen so quick or so completely, that you can't press the panic button. An (old but very active) friend died earlier this year when he slipped and hit his head. Tracking wouldn't have saved him, but it would have determined his whereabouts much sooner. And for a non-fatal blow to head? Tracking could be lifesaving. Or your pack gets swept away in the river with your SPOT? Electronic bread crumbs along the trail and then a track downriver till it hangs up. Searchers could start at the river crossing and the SPOT's final resting location. I also now people who use it to track charter aircraft. Partly for safety reasons – to have a last known location. But also for fleet dispatch and planning. If a plane has to divert, has a headwind, etc; dispatch sees it instantly without the pilot having to make / relay a radio message.

>"but after my Mother-in-law was ready to call out SAR because . . . we realized we needed a way to calm her down."

Sounds like you need to announce trips on a need-to-know basis and she doesn't need to know. Maybe that could be a role for your father-in-law only?

> Not what I'd call the best design… you have to face the screen "away" from yourself to get the strongest signal. Kind of counter intuative. :)

Mike: So (to steal a thought from the 10 essentials thread), we have now determined how a mirror helps you with emergency signaling – to operate your PLB!

[Mike W]

>> Tracking is an option with the Spot – or the Inreach – but plenty of us don't see value in it.<<

I really had to think about the value of tracking when I signed on for my inReach service plan. Unlike the plans available in the USA, inReach Canada has cheaped-out with their plans. If you don't want to go with the $50/month plan (which provides you with unlimited tracking and a ton of messaging), you have to choose between a tracking plan OR a messaging plan.

I decided to go with the tracking plan as I see the tracking feature as providing me with the best safety net, as a lot of my excursions are solo. Turning the tracking on and stuffing the inReach in my pack is how I use it 90% of the time. If I don't return home they will know where to start looking for me.

I also don't do "I'm OK messages". It's something that I've never done in past decades and my family has gotten used to the idea that I'll show up when I get there… and so far so good. With my inReach tracking plan, messaging is barely provided (10 per month) but if I really need to talk, the overage price won't be an issue.

[Will Webster]

"I can see the value in tracking. Stuff can happen so quick or so completely, that you can't press the panic button"

OK; I stated my case a bit strongly. Yes, I agree there can be value in tracking in event of an emergency. There's also benefit in never going out in the woods in groups of less than five (so two can treat an injury while two go for help). I choose to accept a certain degree of risk, which varies with where I'm going and how familiar I am with the conditions I'll face. The difference between backpacking pre-Spot and with a non-tracking Spot is that our families might be spared some worry, and (in the event of an emergency) SAR can be activated quickly and will know where to go (taking S mostly out of the equation). Since the two of us stay together, any sudden incapacitating event would have happen to both of us at once -there are certainly events one can imagine but the odds are a lot better than they are for the solo traveler.

"Sounds like you need to announce trips on a need-to-know basis"

Interesting idea, but since we lost her father a couple years ago, my wife has been checking in with her mother on a daily basis. Disappearing without a word for a few days isn't really an option.

[Randy Nelson]

My SPOT has been pretty darn good at getting message out. I've had 2 fail to get out in 4 years. I don't use tracking but I'm starting to consider it based on some comments here.

All this is based on my experiences since I had one and especially on a trip, solo of course, where I injured my knee and walking was excruciating.

My wife is very familiar with the main rule I have for using the SPOT. No OK messages received means nothing. If I'm in serious trouble, I'm sending and SOS, not an OK. And electronics fail. Don't call SAR until the time specified on the detailed itinerary I leave behind for every trip. Once again, that doesn't change if there is no OK message. There's a map with where I intend to go and possible detours so I'm not tied to my route if I decide I want to go somewhere else. And alternate trailheads I might bail out to. If I decide to take another trail, I start down that trail and I send out 3 OK messages. If it's a bushwhack, I send them fairly often. If she's sees multiple OKs in the same location, spread out over a period of time, I'm not in need of rescue but something is keeping me where I am, like a painful knee. The help message says meet me at alternate trailhead. I changed it to that after the knee injury where I was lucky to hit about a 100 yard window of cell phone coverage and was able to bail out to another trailhead and have her pick me up. Avoided an extra 10 miles and 2000' of vertical by doing so.

I went on a last minute short overnight a month ago and threw the SPOT in my pack without extra batteries. And the ones in it were dead. That was dumb. But when I discovered it in camp, I wasn't worried that SAR would be called. Otherwise I would have had to hike out and ruin my evening. Instead, the worse thing that happened was looking like an idiot to my wife when I got home but were both used to that.

I'd love to get the Inreach if the plans were more reasonable. I think they are pretty steep. Instead of worrying about getting back to my car when I was in camp with my aching knee, I could have just said "Meet me at 11 at TH XXX of road YYY, you'll find it on map ZZZ. And bring some chicken and some cold beer. There's some tables there and we can have a picnic." Now that would be backcountry communication!

[David Miles]

A lot of good discussion here. As a SAR member, we have also had a lot of discussions on the use and types of devices. First, let me say that I like the availability of these devices and that the cost is not too prohibitive. I carry a SPOT with tacking enabled. I like the idea that if for some reason I'm unable to press SOS, at least there is a trail of breadcrumbs. It calms those at home to see the track and know that the SOS has not been sent. However, remember……

1) Know your device's capabilities and how to use them. In the case of SPOT, if you press SOS and then HELP, only the last message gets sent and SAR is not contacted unless your HELP POC calls.

2) Messages are dependent on the receiver POC knowing what to do about it. Let your contacts know that you might rest for a day or two without incident. Send and OK message on a layover day to reassure them. Go over what each message means and how you might intend to use it. My wife always knows my ETA and a time to initiate SAR (usually a large buffer).

3) Be responsible. Almost all SAR personnel are volunteers with jobs. We use precious vacation leave from work to help others. Also be considerate of your family. Life insurance does not pay if we can't find you :(

4) The very best safety item to bring on a hike is another person! No gadget will replace the adaptive response available from and friend :)

5) Your friend's ability to help you (and vice versa) depends on skills and equipment like a good first aid kit.

6) Be Prepared!

[Nick Gatel]

4) The very best safety item to bring on a hike is another person! No gadget will replace the adaptive response available from and friend :)

---

Dang. Double jeopardy.

[David Thomas]

>"The help message says meet me at alternate trailhead. . . . . And bring some beer. "

Randy,

This captures most of my thoughts about the "HELP" button on a SPOT. Without preplanning, I refer to it as the "bring beer" message. I just never know what message I'd want to send, but an alt trailhead is a great idea. Now, if only my wife would ever pick me up! (I was a little slow on a 35-mile day hike due to hundreds of blow-down trees and a missing bridge and I had to hitch hike home).

The best "help" message a friend used on my SPOT was to his wife, "call John Smith and tell him to bring a 55-gallon drum of fuel to Tanana on the Yukon River" in case he had used more fuel than hoped for on a week-long motorized river trip. He wanted the option, but he didn't want to pull the trigger on it if he didn't need to.

[Billy Ray]

"The very best safety item to bring on a hike is another person! No gadget will replace the adaptive response available from and friend :) "

Actually, both are better than either. The beacon (if it works) can get help MUCH faster than any friend can hike out (and while a beacon might not work; it's also possible that a friend will get hurt on the way out and not get out). Then the friend can stay with you, provide medical care, keep you warm.. and/or move you to a place where a copter can land.

Two friends and a beacon are even better… the beacon makes the fastest contact… on friend goes out for help just in case the beacon did not work… the other stays with you.

bill d

[David Thomas]

>" The only thing that I can think of is that it uses the GPS downlink as a proxy. If the GPS downlink is good, then it _assumes_ that an uplink signal will be good. It doesn't know, but it assumes. Since the different satellites are in different places in the sky, I don't know how good of an assumption this is."

Yeah, it seems like one is not equal to the other. But since multiple satellites are needed for GPS fix, does that make it a reasonable proxy for a upload proxy?

Theoretically, could a unit know where the Cospas-Sarsat satellites are? It knows/learns where the GPS satellites are. Then, if it saw GPS satellites on all sides of the Cospas-Sarsat satellite, the upload could be with pretty high confidence. Further, if the unit knew all the orbits, looking at GPS satellites, it could predict when the Cospas-Sarsat satellites would be in the clear. I doubt any unit does this, but they're welcome to steal the idea.

[David Thomas]

>"Two friends and a beacon are even better."

Well, yes and no. Three of you have six ankles that could get broken, not two. Three stomach to catch some bugs. Six hands to disinfect before eating, etc.

Further, there's an insidious effect when we factor in the "added safety" and take more risks than we otherwise would. Examples:

When I was dating my future wife, each of us had a lot of respect for the other's extensive backpacking, hiking, and travel chops. And we each wouldn't "pack for bear" like we would on our own. There was some stumbling down a dark trail when neither of us brought a headlamp. Or no one brought a wallet to the restaurant. Communications helps. As does learning about each other. I don't bring any first aid stuff – I let the doctor handle that. I ALWAYS have my wallet, so she often doesn't. Etc.

Twin-engine-plane engines fail more often then single-engine-plane engines. Pilots and mechanics have long observed and discussed this, and, sure, it's harder to hear an odd sound in one of two engines, but the difference in reliability is greater than that. The thoughtful people I have talked to acknowledge that it's an easy trap to fall into – caring less about the odd sound or errant reading when you have two engines and that it takes a lot of discipline to fight that and fully realize the potential safety of the two engines.

Lastly, I'll ask the guys when they did the stupidest things in a car and I bet it was when there were other people in the car. Especially with no females present. How many people's last words were, "Hey, Guys! Watch This!"?

[Billy Ray]

"Well, yes and no. Three of you have six ankles that could get broken, not two. Three stomach to catch some bugs. Six hands to disinfect before eating, etc."

Don't be silly… you argue from the absurd…

the chances of 6 ankles having problems on the same trip is astronomically less likely… ditto for the other absurd statements…

When you are alone all it takes is one slip to break a leg and if you are off-trail and don't have a friend or a beacon or both or the luck of someone finding you… you are dead. period.

[Ken Thompson]

The more people in your party the greater chance of one of them getting injured.

[Billy Ray]

while the odds of 'something' happening may be greater… the odds of someone not returning alive have been reduced to extremely small… a wise trade…

the problem with making the simplistic and misguided 'six ankles' argument is that it is being made on a forum where the inexperienced could take it and act on it… that could be dangerous and is irresponsible to put it out that way…

bill d

[David Thomas]

Bill: I completely agree that once something bad happens, having more people along it better.

Maybe I phrased that poorly. My point was that more people on a trip create more possibilities for an accident. Not that six ankles would ever get broken. But that one of the three people having some problem is more likely than a single person having a problem. I've done a lot of first aid on companions over the years. Not nearly so much on myself.

If you've seen conflicting data on twin-engine reliability, please post a link. It would be news to me.

" you are dead. period."

Wow. My wife is a zombie. I never noticed. I thought she clenched her teeth and hiked herself off that mountain in Nepal.

[Bob Gross]

"Theoretically, could a unit know where the Cospas-Sarsat satellites are?"

Well, yes, easily. Cospas-Sarsat birds are in geosynchronous orbit. That means that they appear to be hovering at a fixed point in the sky.

"It knows/learns where the GPS satellites are."

That is tricky. The GPS birds are in orbits 50% lower than geosynchronous, so they are not "hovering." They are flying inclined polar orbits, so they are overhead for a while and then gone. GPS birds transmit the ephemeris data in the downlink, so once you've been receiving for a while, that updated information is present. Then, based on that, a GPS receiver knows where the birds _ought_ to be. They can start receiving there and then perfect the PVT solution a little while later. That is radically different from the poor way this was done by the old Magellan receivers of the mid-1990's. It seemed like they had to do a cold fix each time.

"Then, if it saw GPS satellites on all sides of the Cospas-Sarsat satellite, the upload could be with pretty high confidence. Further, if the unit knew all the orbits, looking at GPS satellites, it could predict when the Cospas-Sarsat satellites would be in the clear. I doubt any unit does this, but they're welcome to steal the idea."

Basically, if you have a completely clear view of the sky, then one Cospas-Sarsat bird should be in view. But if you were in a narrow box canyon, you could easily see a few GPS birds and NOT the Cospas-Sarsat bird. I would not say that it is likely, but anything can happen. Better, learn to view your terrain and predict when you are heading into a dead spot. Do satellite tasks before you enter the dead spot.

–B.G.–

[Paul McLaughlin]

Interesting discussion. The real conundrum I see is that any device which requires you to press a button to send a signal is of no help if you lose consciousness. And while tracking like the SPOT can provide could help in that situation, it's not in all likelihood going to bring help fast enough unless you have left instructions that SAR should be called the instant that a scheduled tracking message is not received (which does not seem like a good idea) If you are unconscious for as long as it would take for you to be found, even with the tracking points to guide rescuers to you, it's probably a body recovery and not a rescue that will occur. An injury involving unconsciousness is where a companion is of the greatest help, and where a signalling device is also of great help, since the uninjured person can press the button, and then stay to help the injured person.

I carry a PLB – having had a poor experience with the first generation SPOT – but I carry no illusions with it. If I break a limb and am able to operate the device, it will probably bring help in time for me to be rescued. But I know that many things could happen for which it will not make any difference, and in some cases I might be able to send the signal and still not have help arrive in time to save me.

When I travel solo, I consider that I am carrying the PLB for the sake of my family and of the SAR personnel. In a group, it becomes mostly for the sake of my companions. As for me, I accept the risks and always have. I do not go into the wilderness lightly, I prefer to open my eyes to the real risks and make the decision that it's worth it to me to have the experiences I can get no other way.

[Rex Sanders]

NOAA map of all USA-related rescues triggered by PLBs, EPIRBs (boats), and ELTs (planes) in 2012, with short stories about each rescue. Before you look, guess which state had the most PLB rescues?

http://www.nesdis.noaa.gov/sarsat_rescues_2012.html

Almost all the PLB stories in the lower 48 involved injury or illness. Most of the Alaska PLB stories start with "An individual activated a PLB when his snow machine became disabled." Also note the importance of keeping your registration up-to-date.

PLB/EPIRB/ELTs use both LEO and GEO satellites:
http://www.sarsat.noaa.gov/satellites1.html

"The keystone to the Cospas-Sarsat System are the low-earth orbiting (LEO) satellites from which the system takes its name."

"… a GPS-equipped beacon only works when the receiver has a clear view of the sky in order to permit the receiver to self-locate. Often times, conditions do not permit this which may either distort the positional accuracy or negate it altogether. Because of this, the Cospas-Sarsat System relies upon the Doppler locating effect as the primary means for locating a beacon [via LEO satellites]. This process is able to overcome the limitations of a GPS unit and still generate a fairly accurate location…within a mile for positional accuracy."

Comment: We have seen limitations for alternative devices that depend completely on GPS, e.g. SPOT, InReach, Cerberlink. With two-way devices, you could also send your location as a text message if GPS is wonky.

— Rex

[David Thomas]

Rex: I guessed the correct state. But, Wow!, half the land rescues are basically from one 3,000-person town, or at least their 6,000-person borough.

Edited to add a thought: with so many rescues in and around Barrow, I went to check on its current local-option status. Currently damp (it goes from wet to damp to dry). A tidbit off a reliable-looking website, "A bottle of liquor costing only $10 in an urban liquor store will sell for $50 in a damp hub-town like Kotzebue or Barrow, and more than $150 a in a dry village like Point Hope or Selewick." So how many of those rescues were of bootleggers?

Bob: so the Cospas-Sarsat satellites are geo-sync? What about polar coverage? Aren't geo-sync satellites over the equator? So at may lat of 60.5N, they would be a maximum of 29.5 degrees above my horizon? And, within one area, it would always be at a fixed bearing and height?

Something could be 25,000 miles out, but in a polar orbit, but then wouldn't be geo-sync and a constellation of them (3 or 4?) would be needed to continuously cover both poles.

[Zorg Zumo]

And all but 3 rescues were because of piece of junk snowmobiles. Looks like the locals around there use the Cospas-Sarsat system to call for taxis. An expensive tax-payer funded service for Alaskan rednecks who don't maintain their machines (or don't carry enough fuel).

I didn't see one injury-related call.

[Stephen M]

I normally carry my Plb in my pack, but should I have it in my pockets or around my neck?

[Author]

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