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Emergency Transmitters / Locators - 2015

Posted: Jun 04 2015 12:41 pm
by chumley
The HAZ Forums frequently feature questions about emergency transmitters and locators.

Since technology changes quickly, previous discussions become outdated. Researching older threads can be helpful, but it is also nice to find the most current information with ease. Let's keep discussion on this topic in this thread. It will be archived and a new thread started when new technology changes the game again.

Basic Technologies:
SEND: Satellite Emergency Notification Device
PLB: Personal Locator Beacon

PLB is the simplest to explain because it really only does one thing. It is used exclusively in an emergency and sends a signal on a global emergency network that can only mean one thing. You need help and need it now. Part of the data it transmits (besides your location) is identifying information so rescuers know WHO you are ahead of time. An additional feature of the PLB is that it has a local homing beacon, so when rescuers arrive to the area (100 meter accuracy) you transmitted from, the beacon on your device directs them to your exact location. This could be useful in heavy brush, etc.

PLBs cost more to purchase, but there is no subscription required. The battery generally lasts for 5 years or so, and replacing it currently costs about $150. But it's one of those pieces of equipment you hope to never use.

In the technical nitty-gritty of it all, PLBs communicate on a global emergency network run and monitored by governments. PLBs transmit at about 5 time the power of other tranmitters. For pure emergency locating, PLBs simply have no competition.

The most popular brand of PLB is the ACR ResQLink (there are several versions).

SENDs on the other hand are generally used to communicate via satellite -- In emergencies AND non-emergencies. SENDs provide extra features that some users desire, primarily the ability to send "peace of mind" messages to loved ones, or other features including mapping, tracking and waypoints. For those users, SENDs are extremely popular options. But --SENDs require fee-based subscriptions to transmit communications. Let's break them down into ONE-WAY and TWO-WAY communicators.

ONE-WAY communicators allow the user to send messages to the satellite network that are then delivered to pre-determined users. Emergency signals are forwarded to rescue personnel. Non-emergency messages can be simple messages such as "I'm OK" and are sent by text message or email to family or other pre-designated users. Some devices send only pre-programmed messages, while others will pair with a smart phone and allow custom messages to be sent. An example of a one-way SEND is the SPOT Gen3.

TWO-WAY communicators do everything that ONE-WAY communicators do, but also allow the user to receive messages over the satellite network. This can obviously be helpful both in emergencies and non-emergencies. An example of this kind of SEND is the DeLorme InReach.

In the technical nitty-gritty ... SENDs transmit their data to commercial satellite networks that do not always have global reach. This is why they require a subscription fee. DeLorme uses the highly-reliable Iridium satellite constellation and SPOT uses the similar Globalstar constellation. The messages are received by a third-party and then forwarded to the appropriate entities. Think of it as On*Star for your hike! They transmit with a power level that is only about 20% of that of a PLB. This makes them more susceptible to not acquiring your location, or not sending a message when desired.

I should add that I don't personally own one of these devices and what is written here is just a brief summary of my research. I'll gladly correct anything that is incorrect. But feel free to discuss this topic here and include your own information, experience, and knowledge.

Previous forum discussions on this topic may be viewed here:

Re: Emergency Transmitters / Locators - 2015

Posted: Jun 05 2015 12:26 pm
by The_Eagle
chumley wrote:AZ Wandering Bear wrote:
I am neither an engineer or Chumley
Good, one is plenty.

I have someone at home that worries when it's taking me longer that I advertised. It's happened more than just a few times and the authorities have been called on my behalf previously.

For me, a PLB does NOT fit the bill.

I use a SPOT 2 with my pre-programmed messages. Being able to send my "I'm still hiking and doing OK" message via Email and Text, is paramount. A message when I start and a message at lunch.
We have a code that if my hike is running longer than expected, I will hourly send the above message.
At the end of the hike I'll send a "I've finished hiking for the Day" Text / Email.
I pay for the tracking feature in the event I can't push a button. Just trying to make it easier for them to find my carcass.
I've never had to push either the "Help" or "SOS" Buttons.
My Help button is programmed to send a request to come get me for non-life threatening occasions (ie car problems).
I have this going to a wider crowd with vehicles that can handle where I might be.

The MOST important thing for my SPOT is to keep fresh expensive Energizer Ultimate Lithium Batteries. They seem to have a slightly higher voltage are are the only batteries that work rather consistently.

I found the SPOT plans at the time I purchased, to be more affordable.

Re: Emergency Transmitters / Locators - 2015

Posted: Jun 07 2015 8:26 pm
by big_load
AZ Wandering Bear wrote:SPOT and InReach both have a feature that transmit your position on some preset schedule.
One of my CO buddies received an unexpected SAR visit on a remote island in Alaska a few years ago. He had dropped his SPOT and was unaware of it, so his track went static for a couple days. He was greatly chagrined, but it was a difficult decision for those back home. The people monitoring him was a whole team of experienced backpackers, so there was a lot of discussion before making the call.

Re: Emergency Transmitters / Locators - 2015

Posted: Jun 08 2015 2:25 pm
by AZWanderingBear
There are always issues with electronic gadgets. If I remember right on the first SPOT design it was way too easy to accidentally trip the SOS button and not know it. Then you get surprised when a whole bunch of helicopters and guys with serious looking packs showed up and were quite unhappy. The InReach solves a little of that kind of stuff with the two-way capability, but it can still fail. My "responsible Individual" has pretty straight forward guidance on when to call in help and when not to. Though I don't carry any electronic communication device now beyond my cell phone. If I did a serious multi-day trip alone in the future I might reconsider that.

Re: Emergency Transmitters / Locators - 2015

Posted: Jun 13 2015 12:33 pm
by Thoreau
Just chiming in on the technical side with a quick observation...

Based on a very quick google search, it looks like PLB's operate around the 70cm band (a little lower, 406mhz) while SPOT is up in the ghz range. Neither one would be affected in any meaningful way by the atmosphere at any level. There are more than a few amateur radio satellites up there that run in the same area of the spectrum as PLBs and they're easy enough to hit with a handheld radio, with a lot more bandwidth (voice) than any of these rescue devices would need.

That said, as a radio nerd as well, the technologies worry me a lot less than the specific networks. SPOT just doesn't have that good of a sat network and the 95% rate previously mentioned is okay for a breadcrumb beacon, but not so much for that one emergency signal (they do repeat obviously, but if the location is a no go, that isn't gonna change as time goes on and subsequent transmissions are sent unless other variables change.)

For a pure rescue beacon, I'd go PLB, hands down. Unfortunately I'm a bit of a nerd and find the DeLorme 2-way option to be more useful all around, so eventually I'll be going that route.

Also worth mentioning that I've got a Gen 1 and a Gen 2 SPOT sitting at my desk that I used briefly and couldn't be bothered to reactivate. Between always hiking in groups and also having ham radio on hand, I figure most risk is mitigated well enough for now, until I can scrape up the moola (initial AND recurring) for DeLorme.

Re: Emergency Transmitters / Locators - 2015

Posted: Apr 07 2016 7:11 pm
by MtnBart01
El Paso County Search and Rescue used an interesting way of locating a lost hiker. They had the person open the location services on their iPhone compass app which then provides gps coordinates. Article is on their Facebook page linked off their website. Never thought about it and don't think I've ever used the app on my phone.
Barr Camp caretakers were then able to get to the person and warm them up. :)

Re: Emergency Transmitters / Locators - 2015

Posted: Apr 07 2016 8:36 pm
by chumley
I'm surprised an iPhone that dials 911 doesn't automatically transmit that data.

Re: Emergency Transmitters / Locators - 2015

Posted: Apr 07 2016 8:37 pm
by big_load
It would be great if Route Scout explicitly displayed UTM coords. (Or maybe it does and I couldn't find it).

Re: Emergency Transmitters / Locators - 2015

Posted: Apr 08 2016 11:03 am
by rcorfman
chumley wrote:I'm surprised an iPhone that dials 911 doesn't automatically transmit that data.
By law, it does. However, we don't know if the person dialed 911 or not, or whether the SAR team was relayed any of that information from the 911 center. They probably figured it would be easiest to get the coordinates from the horses mouth.

Re: Emergency Transmitters / Locators - 2015

Posted: Apr 11 2016 7:29 am
by Espi
Every time you dial 911 your coordinates are displayed to the call taker. The information is released in two phases. Phase 1 is not as accurate. This is the location of tower that is handling the call. Phase 2 is the location of the device that is placing the call.

In the 911 center that I work in, the call taker often has to rebid for the phase 2 information.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 02 2016 8:47 am
by xthine
I was looking at SPOT and ACR. I ended up choosing the Delorme InReach Explorer because of 2 way communication and ability to upload routes.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 02 2016 8:13 pm
by big_load
I renewed the registration on my PLB before my last trip. I wish the registration period mapped better to the battery life.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 13 2016 11:32 am
by RowdyandMe
I have a Spot 3 that is coming up for renewal. And now I am thinking about getting something different such as something with two way communication.
Any suggestions would be appreciated

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 13 2016 6:24 pm
by Sredfield
I don't intend to renew my SPOT subscription either
since they raised the cost 50%. Will find something with communication and a better subscription plan.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 14 2016 8:24 am
by RedRoxx44
I haven't used my Sat phone much so it mostly sits at home. The pricing for air time is not attractive as it was last year but I am happy with the phone; I got a good price on Amazon for it in a hard case with an extra battery and charger. The times I have used it voice quality is excellent. So many places I go my cell phone is basically a brick with no service, even with Verizon. I can remember the old days with a Verizon flip phone ( pre any data plans) for 18.00 a month and I could make a phone call from the Maze in Canyonlands at Dollhouse One campsite. Bet I can't do that now.
I guess I will pony up with more consistent airtime and take the phone so I have it just in case. But I am not hiking with it-- it'll stay in the car for such trips as Parashant, etc.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 14 2016 10:09 am
by RowdyandMe
I am looking for something that is reliable as I hike mostly by myself and of course Rowdy.
I was just lucky when I broke my ankle that I was not alone.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 14 2016 2:36 pm
by CannondaleKid
RedRoxx44 wrote:I can remember the old days with a Verizon flip phone ( pre any data plans) for 18.00 a month and I could make a phone call from the Maze in Canyonlands at Dollhouse One campsite. Bet I can't do that now.
A year or two ago I would have agreed... 3-5 years ago I rarely bothered to check cell service on most hikes because there was none or very limited but that has been changing fast.

But for what its worth, when we did the hike from Dollhouse to the Green/Colorado Confluence in May there was service for both Verizon and AT&T (I think that's what another hiker we met had) from almost every high area along the way.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 28 2016 2:11 pm
by RowdyandMe
Does it let you send lm ok to family? Or is it just for rescue?

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 28 2016 6:55 pm
by wha
By itself the ResQlink is just for rescue. You can subscribe to a service like which can send "OK" messages to a recipient, but the total number of messages are limited so that the battery is not run down too far (only 12 messages with a gps fix, for example). Read the FAQ and other information on the site. If I had a PLB, I would not use this.

What I do have now is the inReach. In a previous post I show some statistics on the reliability I found with a gen 2 SPOT over 200 messages. I don't have as much data yet on my inReach, but so far it's not looking too bad.

71 messages sent, with accurate gps fix
1 message failed to send after 15 minutes

The great thing about the inReach, with the 2 way communication, is that I knew those 71 messages went out, and usually within a minute. I also knew that the one failure didn't go. I was in a valley, surround by tall pines, with heavy rain clouds overhead. I moved a couple hundred yards to a small clearing and then a message was successful.

I have the Safety Plan. It only includes 10 text messages per month, but there are unlimited Preset Messages allowed, so I can send as many "I'm ok" messages as I like. I also mostly hike alone, and I am more concerned with somehow being incapacitated and unable to activate a PLB. At least with a string of ok messages from the inReach it would narrow down the search area when people realize I'm missing.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 28 2016 8:32 pm
by RowdyandMe
I have a Spot Gen 3 and pay like $150. A year for the service. I need the ability to send I'm ok as my wife gets really worried if she doesn't hear from me.
She has called search and rescue just because I was late and I don't need that.

Re: Emergency Transmitters / Locators - 2015

Posted: Aug 28 2016 11:13 pm
by wha

The inReach with the Safety Plan will do that for you. With tax and fees it's about $13.50 a month for the service, or about $12 more a year than the Spot. You get 3 unlimited preset messages like with the Spot, but you get confirmation back that the message was received by Delorme's system. You also get 10 text messages per month for when a preset message just won't do, and you can receive replies (which do count as another message). You can also have your account set so that someone can "ping" your device ($0.10 each ping) and it will locate you on a map as long as the inReach is turned on. There is a higher initial cost for the device, but after that, the yearly plan price is almost the same as Spot and you get so much more with the inReach.