Diet Taco... trying to keep things light

Happy New Year to you and everyone else as well!

No, seems too early to plan for anything as yet. Going to have to wait to see how long vaccine roll out takes and hopefully a drop in the insane infection rates. There's just too much virus in the community right now for me to seriously consider making a cross country trip by any convenient mode of transportation. It would probably be OK to drive myself across sleeping in the vehicle the whole way but that would be six days round trip before I did a single bit of camping. Can't realistically be gone for the two weeks or so plus necessary quarantine upon return without a lot of impact to the family. Plus I've got both my work and my daughter's school policies regarding non-essential travel to consider. Just doesn't seem sensible or appropriate to do and I don't see when specifically it is likely to be better enough.

That said, I'm hopeful that by very late spring or early summer I might be vaccinated and the community transmission rates low enough that combined with vaccine effectiveness it would be at least borderline responsible to do. Of course given how 2021 appears to be starting off in competition with 2020 for insanity I'm not going to hold my breath.

Anyway - it's a first world problem for us! We are all healthy, financially stable and either employed or in school still. No extended family members impacted so far thankfully. In the grand scheme of things missing my luxury trips to the desert is far, far down the hierarchy of needs...

I'm missing them too

 

Communication device. What do you recommend for emergencies or to send a text to my wife if there's no service. Have a little bit of extra cash trying to avoid modifying the truck instead I'd rather buy some useful camping/safety gear for the truck. Also check out your fire extinguisher setup

 

I have a Garmin InReach satellite communicator and am very happy with it!

 

That's the one I'm checking out right now!

 

For a single "do it all" device I also would recommend one of the InReach devices. I have the InReach Mini which I like because it is ludicrously small and I don't need any sort of maps screen since my phone already provides that and I prefer to keep "navigation" batteries and "emergency" batteries separate rather than having them all wrapped up in one.

The InReach devices use Iridium for their satellite communications which I greatly prefer to the GlobalStar based SPOT devices. There are reasonable low usage plans for InReach if you just need to send an occasional message on infrequent trips.

For actual emergency communications a number of people have said having the two way messaging is a great help in any sort of SAR response compared to the blanket one-way "save me" message that an EPIRB would give. The EPIRB is probably more bullet proof for getting an SOS and a coarse position fix in an emergency with very poor sky access (e.g. slot canyon) and there is no subscription costs for an EPIRB but it is does only one thing and doesn't provide any messaging capabilities.

EDIT: I’ve revised my opinion about whether an EPIRB/PLB would actually be most reliable with poor sky view: PLB vs Iridium

The one weakness with the InReach Mini specifically is that its GPS antenna or GPS RF front end sort of sucks nuts. It does the Iridium part very well (it is based on an already integrated Iridium modem module so it would have been sort of hard for them to screw it up really) getting messages out in appropriate amounts of time even with limited sky access. The GPS however is another story often taking vastly longer to get a fix than my iPhone does with limited sky access (e.g. in a canyon). Because by default the device will wait until it has a GPS fix to send a message you can get fooled into thinking Iridium is the issue. It isn't. Iridium is rock solid. For some reason though Garmin, despite primarily being a GPS manufacturer, seems to have screwed the pooch on the GPS end of things. You can always override and send a message without a position fix so it is more of a nuisance than a critical flaw. I'm not sure if the other InReach devices are more reliable in this regard.

 

Awesome information thanks. Going with the Mini it looks like. Should be good enough paired with my phone

 

InReach. I can use mine stand alone or with my phone (App required)

 

Diet Taco is ALIVE... apparently...

Well, I'm not the one moving it, but it is moving. Haven't seen or heard from the truck in 15 months but just now it moved finally! Where I store it vehicles are densely parked and occasionally they need to move one vehicle to access another. The asset tracker I have on the truck just sent an alert the truck moved, so at least I know that it still exists and can be started. Amusingly I was just in the middle of doing some minor edits to this thread for the first time in ages when the movement alert came in. It was as if Diet Taco's side-view mirrors were burning or something.

In other news, at the risk of jinxing myself, I hope to do a trip in June. You know, because June is such a delightful time to be in the desert... I'll take pretty much anything at this point. It's good to be planning a trip again.

 

..nothing like landing into DRY HOT air after a flight from stupefyingly humid baltimorean heat...welcome back to the western world...in advance

 

Emergency Satellite Communications Link Budget Analysis
Maybe a PLB isn't the most reliable option for a hiker...

Having now wasted too much of my time scratching an engineering itch I figured I better at least capture it somewhere. Whether it is of use or even understandable to others is perhaps an open question, but I'm going to post it anyway.

The TL;DR is that despite PLBs having the online reputation of likely to be more reliable in an emergency that actually for the case of trapped in a canyon or other terrain with limited view of the sky Iridium based beacons like InReach are probably more likely to successfully connect sooner.

At present I consider either a PLB or InReach to be the best options for emergency satellite based communications so I'm leaving SPOT out of the mix though it is quite functional as well. PLBs are a one way device that can only be used in a true emergency and require no subscription. InReach is a two-way device that can be used for routine communications as well as in emergencies and requires a subscription.

A constant question has been in an honest to goodness emergency would the LEOSAR, MEOSAR and GEOSAR based PLB or the Iridium based InReach be more robust. The general consensus online has always seemed to be that the PLB should be more robust based on the fact that it emits 5W as opposed to InReach devices which emit 1.6W. But of course that's only one part of the communications link, there is the whole question of the capability of the satellite that receives the transmission as well as the efficiency of the modulation and coding used for the transmission.

All of these options will work great and quickly with clear sky view. In the marine environment this is pretty much always guaranteed. There is no need to do any analysis for this as both systems have plenty of margin in such a situation.

For a hiker though the question is often which will work best with a severely restricted sky such as in a deep canyon. In this scenario there are two possible means for a message to get out.

First, you could get a lucky pass of a satellite that passes through your tiny window of sky. For this case what matters is how likely is that to happen with the particular satellite constellation. In this case Iridium is the clear winner with a constellation of 66 operational satellites compared to just six LEOSAR payloads (MEOSAR and GEOSAR are less favorable in this condition and so aren't considered). You are effectively about ten times as likely to end up with a favorable Iridium pass.

Second, your transmission could reflect or scatter off the canyon wall to find a path that isn't a direct line of sight. In this case the reflected signal will be significantly attenuated so the question is just how much margin there is in the link such that you might still get a message out despite the attenuation.

In satellite link analysis we always have what is called a "link budget" which is an accounting of all the gains and losses in the system for a given scenario which computes the amount of signal to noise available at the demodulator and compares that to the minimum signal to noise required to successfully demodulate the message. When folks say the PLB is better because it emits 5W instead of 1.6W that is only looking at one entry in the link budget. It is as if we evaluated businesses only based on their revenues and ignored their expenses (though admittedly that is a popular thing to do these days).

Typically a link budget is computed for the "worst case" for a system to ensure the system will still work in that "worst case". Often there is a lot of margin (i.e. far more signal power available than needed) in more typical situations. And the "worst case" can be very different for different systems because what the "worst case" is really depends on how you intend to use the system.

Neither Iridium nor LEOSAR consider transmission in a canyon to be their "worst case", rather they write it off as an irrelevant case. Instead they model their worst case as direct line of sight to a satellite being low on the horizon since that gives the longest path distance. But for our trapped hiker what really matters is when a satellite is nearly overhead (typically a best case) how much extra signal power is there such that we might close the link with reflection off of terrain rather than direct line of sight? We will need to compute our own link budget for this situation.

With much digging I've found adequate references to do a simple link budget for a satellite directly overhead with direct line of sight:

LEOSAR

PLB EIRP: 7.0 dBWi
Free Space Loss: 142.6 dB
Polarization Loss: 4 dB
Fading Loss: 2.5 dB
LEOSAR G/T: -32 dB/K
Boltzmann's Constant: -228.6 dBJ/K

Computed C/No: 54.5 dBHz
Required C/No: 36 dBHz

Margin: 18.5 dB

Iridium NEXT

InReach EIRP: 2.0 dBWi
Free Space Loss: 154.4 dB
Polarization Loss: 4 dB
Fading Loss: 2.5 dB
Iridium central spot beam G/T: -8 dB/K
Boltzmann's Constant: -228.6 dBJ/K

Computed C/No: 61.7 dBHz
Required C/No: 42 dBHz

Margin: 19.7 dB

Conclusion

Likely the above is Greek to almost any reader here. The key numbers above are the margins, this is the amount of attenuation the links can tolerate and still close. Note that Iridium's is slightly higher than LEOSAR despite the PLB emitting more power than InReach. If you aren't familiar with a dB scale the 1.2 dB difference there is a factor of 1.3 and is well within the likely uncertainties of these numbers. So the systems have essentially the same performance with a satellite directly overhead and the same amount of margin to give up to attenuation for a reflected path rather than direct line of sight.

So despite the fact the PLB emits more power actually the InReach is slightly more likely to connect without line of sight. The reason is in that G/T number which is a figure of merit for a receiving platform. LEOSAR is just a small payload that is hosted on things like weather satellites and it therefore has only a small low gain antenna. Iridium is a purpose built communications satellite with all its mass and volume dedicated to communications and thus has effectively a very high gain antenna (actually it is a phased array antenna with multiple spot beams but same difference).

Another important factor here is that both systems have quite a bit of margin when the satellite is nearly directly overhead. That means there is in fact a chance that you might connect without line of sight. The Iridium margin of nearly 20 dB means that even with reflection only providing 1% of the power of a line of sight path the link would still close. That's a potential amount of attenuation on a glancing path off of a canyon wall. If the margins were only say 3 or 5 dB then we'd say it was very unlikely reflection would ever be good enough to close. But at 15 to 20 dB there is probably a reasonable chance a canyon wall would be a good enough reflector to close the link.

Add to this the fact that there are far more Iridium satellites than LEOSAR satellites such that you are more likely to end up with a favorable geometry and it appears pretty clear that Iridium is rather more likely to get a message and get it sooner than LEOSAR in a restricted sky environment.

Some details for the curious...

I felt it would be a bit over the top to explain link budgets in this post, but feel free to ask any questions and I'll try to answer them best I can. For anyone in the future who does understand link budgets that might stumble upon this in the future I'll provide some source details.

For both systems I assume the beacon antenna linear polarized (PLBs are in fact while I'm assuming that InReach is as well since their antennas seem too small compared to the wavelength to produce an efficient circularly polarized design) and both systems have circularly polarized antennas on the satellites. This is fairly common for mobile satellite designs and is reflected in the 4 dB polarization loss in the link budget (this 4 dB actually in the Copas-Sarsat documentation).

The LEOSAR numbers mostly come the publicly available Copas-Sarsat documentation specifically C/S T.014 Annex H where a link budget for an elevation of 5 degrees is given. I've modified the G/T to account for slightly lower performance directly below the satellite based on antenna patterns shown in C/S T.003. I've set the required C/No based on an Eb/No of 9 dB which may be a bit favorable for the SARP-3 processor. There seemed to be inconsistencies in the documentation for SARP-3 performance (namely it references a 300K system temperature when in fact the system temperature is actually 1000K and the numbers in the documents make more sense if we use 1000K). The SARR "bent pipe" path is theoretically a bit disadvantaged compared to the on board SARP processor so I assumed SARP processing.

The Iridium numbers assume the same polarization and fading loss as the LEOSAR case though likely the fading is slightly lower at 1600 MHz compared to 406 MHz, so slightly disadvantaging Iridium in the comparison. The G/T comes from a FCC 312 Schedule S submitted for the Iridium NEXT constellation, specifically in this case one of the central beams which have a lower G/T than the edge beams. The C/No is based on an Eb/No of 8 dB which is based on a theoretical Eb/No of about 7 dB for BER of 1e-5 for the BCH(31,20) FEC used in SBD messages.

In summary I've made slightly favorable assumptions for PLB/LEOSAR and slightly unfavorable assumptions for InReach/Iridium and in the end InReach/Iridium still came out on top by a bit.

Now, one unaccounted for difference here is that the PLB transmits blindly once every 50 seconds while InReach needs to acquire the satellite downlink before attempting to transmit. If the InReach never acquires the satellite downlink it will never attempt to transmit as far as I can tell. I am assuming that the reflected channel is nearly symmetric so if the path to transmit exists the InReach will also acquire the downlink. Additionally the 9603 modem documentation (used in InReach devices) implies the downlink margin is about 6 dB higher than the uplink so this is probably a reasonable assumption.

 

@DVexile Ken, I always enjoy your well thought out and informative posts. The few recent ones on InReach and PLB have had some very good information. I just wanted to let you and the others who may be interested know about an app that can help greatly with the InReach. The app is called “Orbit,” it’s in the Apple App Store, I don’t know if there is a Google version. The app is actually intended for astronomy to help identify satellites as they pass overhead.

You are able to select different satellites to be the only ones displayed, the Iridium array being one of them. From there you see the orbits of the satellites in relation to your position on the globe. The satellites will also be advancing around the globe in real time on the display. You can tap a specific satellite and see it’s orbit, the actual ground path it follows, and the area of the globe that it’s antenna is covering. This is very helpful to determine if your signal is going to get out immediately or if you are in a current dead spot due to no satellite coverage. If you are in a dead spot you can select different satellites to help determine when an antenna will cover your area. I realize in a critical emergency you don’t have time to analyze this, that’s when you just need to hit the SOS button and let the system do it’s thing. This is just one more tool to help understand and visualize why the messages may be delayed or when you have the best chance of sending the nightly “I’m OK” call to your significant other.

FWIW, I’m retired Coast Guard and will soon be retiring from my Sheriff's Office. I’ve done SAR work and been a SAR Coordinator with both. I encourage you to get a PLB or an InReach and carry it with you all the time when you are out and about. For me, the extra messaging abilities of the InReach make it a better choice for the way I travel.

Screenshot of the app showing my location, selected satellite, and the actual ground coverage of its antenna

 

@Cwopinger thanks for the excellent post! Yes the various satellite apps can be great at figuring out how things are going to work out in the sky. And actually really great at showing just how more robust Iridium is likely to be when trapped in a canyon (see further down in this post).

A word of warning though for Iridium. Many satellite apps mainly included Iridium for flare predictions which only the first generation satellites produced. As a result many apps do not actually show the current second generation satellites which are the operational constellation. Most of the first generation constellation has been de-orbited at this point except for twenty-something that were failed to the point Iridium could no longer control them which remain in orbit (some tumbling actually) and will not decay for many decades or centuries.

First generation satellites are numbered below 100 and second generation above 100. So if your app shows you a satellite numbered below 100 then that is not an operational satellite (e.g. in the previous post Iridium 42 is selected which is an inoperative first generation satellite). You'll only want to pay attention to satellites numbered above 100 and even then be aware there are inactive on-orbit spares in each orbital plane. In an app you can usually distinguish the on-orbit spares as they will be at an odd spacing from the other 11 in the orbital plane.

Again the catch is some apps will only show you the remaining first gen satellites since the apps focused on flares. Make sure your app is showing you the second gen (also called Iridium NEXT) satellites numbered above 100.

As for app selection there are a bunch that want you to subscribe rather than just buy once. Orbitrack from Southern Stars is a "purchase once" non-subscription app I'm using that appears to be getting regular updates still. I did some screen recordings to illustrate Iridium vs SARSAT as far as sky view diversity goes.

First up is the Iridium constellation. Note the time marks at the bottom, initially it is playing relatively slowly. I've selected one satellite in an orbital plane so the app will continuously show its orbital path as a line across the sky and that line essentially shows the path for all the satellites in that plane. You can see the actual individual satellites labeled moving along that plane. I started with the plane close to crossing zenith and note how the frequency of satellite passes means that even a small patch of sky will eventually get visited by a satellite. You can see the leading and trailing orbital planes on the east and west horizons (though there isn't a line there you can see the individual satellites). You can a see a few of the first gen inoperative satellites fly through as well. The orbital planes pass zenith every two hours so again if trapped with very little sky view it is very likely within a two hour period you'll have visibility on a satellite.

I accelerate time at the end of the video so you can see multiple planes pass over.



Next up is the SARSAT constellation. SARSAT is again just a payload on other satellites so they aren't labeled as "SARSAT" or "LEOSAR" or such. Instead this app has a group you can select for satellites that host a SAR payload. In this recording you can see the GEOSAR satellites that appear to not move at all, these are geostationary satellites and as you will see these are typically the only satellites you expect to see you immediately when you activate a PLB. I've selected one of the GEOSAR and its line roughly represents the "geo-belt" where all geosynchronous satellites live. LEOSAR are the satellites at orbital altitudes similar to Iridium and there are just six of them so we will see them much less often than Iridium. In fact I didn't get a pass at all until I sped up the time at which point you can see they do come by often enough but many patches of sky don't see them for very long periods.



Now MEOSAR is going to be coming online which are payloads hosted on geonavigation satellites like GPS and Galileo. This will give a much more frequent revisit rate to regions of the sky but presently is not considered operational and has a lower link budget than Iridium if we were in a "no sky" situation and depending on reflection off of canyon walls to get a signal out. As far as I can tell MEOSAR is actually being used and has been for some years despite not being declared "operational".

Again, thanks @Cwopinger for bringing up a really useful topic!

 

Ken, once again wow! Your depth of knowledge is incredible and very informative. Considering where you live and this knowledge of satellites, do you work for a 3 letter government agency in the Ft. Meade, MY area? Lol.

I knew there were new Iridium satellites in orbit but didn’t realize so many old ones were inoperative or deorbited. I was also aware many of the astronomy apps are designed for the antenna flare visibility but that also meant the antenna should be able to pick up the InReach signal. I will need to rethink my strategy and will be looking for an updated satellite tracker app, I’ll check out Orbittrack for sure.

 

Do these apps need internet connectivity to work or do they download the orbit data so you can have accurate information when in absence of cell service?

 

@Cwopinger - It's actually my wife's fault (i.e. job) that we are in Maryland! The small company I work for is based in AZ where we used to live but they kept me on when we moved out here. But I am an EE and the company I work for does a fair bit of satellite communications related stuff so it is familiar ground for me. Though I wasn't personally involved a few years ago we even did a cubesat payload to detect EPIRBs.

@EdinCincinnati - Orbitrack at least, and I believe a fair number of the others, don't require a continuous internet connection. They periodically download updated ephemeris for the satellites which is typically accurate for many days going forward. Most satellite orbits are very stable for longer periods of time unless they are very low orbiting.

 

Day pack/ Hiking Emergency Gear
Version 2.0

Well when some asshat stole stuff out of the back of the truck a year ago one of the things they got was my daypack. So I've had to recreate that and in doing so have made a few changes and improvements that might be helpful for others. The rationale behind what is and isn't included is still the same and is outlined in the original post describing the first version.

First up is the emergency kit:



Changes from the first version:

• Orange outer bag to be easier to see when set down
• Somewhat better mini-first-aid kit
  
• Space blanket bivy sack a bit more durable and orange
• Slightly more compact PLB
• Folding scissors now included (TSA approved)
• Different mixture of fire starting materials
• Included some durable, shelf stable, sugary snacks

You can't see it in the photo but I've added extra band-aids to the first aid kit. It is very common to end up with small cuts on hikes so I like to have a handful along at all times. I store the folding scissors in the kit as well.

In the last version the space blanket was ultra thin and just plain silver. I wanted to have some sort of orange signaling cloth as well but it turned out that that most compact and lightest weight approach for that was to just get an orange bivy instead. This one was significantly pricier coming in at about $15 rather than less than $5 for the other kind.

That said in the process of researching orange signaling cloths I found a someone had recommended a great lightweight solution of

$9 emma kites Fluorescent Orange Ripstop Nylon Fabric 40 Denier, Precut Piece 1-Yard: 60"x36", Ultra-Light Airtight Water Resistant Tear Proof, for Kite Flag Stuff Sack Bag Inflatable Windsock Pack Cover

neon orange kite fabric. I did buy some since it is so cheap and I think I'm going to cut a few squares from it about a foot square to carry with me to mark turns on hikes. I usually make small cairns which I tear down on my way back but I've occasionally walked past them so something more visible would be nice.

The RescueMe PLB1 is a somewhat more attractive form factor to me than the ACR one I had previously. In the PLB1 the antenna actually coils up in the device whereas on the ACR it wrapped around the outside and was insufficiently latched such that it often sprung out.

As mentioned in the previous post if I put a small pocket knife in here I'm guaranteed to forget that at some point and lose it at the TSA checkpoint so instead using folding scissors is better than having nothing.

I saw a recommendation that those little circular face cleaning pads make excellent fire starters so I threw some of those into my fire starting kit.

Also based on recommendations from the last time I posted I put a few extra sugar snacks in. I always have a bit of food with me and bring a little extra but someone made the excellent suggestion that some "just in case" sugar boost can really make a miserable night out a tiny bit less miserable and clear your head if fatigued.

As for the rest of the pack it is also similar to before:



I'm now using the REI Flash 22 pack which is actually a bit lighter than my original pack. I actually like it quite a bit. I upgraded my rain pants to OR Helium pants. These are a couple ounces heavier than the old pants but also far more functional.

I changed the Platypus solution as well. I was not a fan of the Big Zip that I used to use as getting the zip closed was quite a pain to be honest. This new bladder just has a spout on it which should be fine since I only ever carry water so cleaning is quite easy. I did, however, change out the mouth piece and this was something I really did like about the Big Zip setup I had as there was a manual valve on it to reduce leaking.

I forgot to include my head lamp in the above photos, but that of course is still part of the kit.

Total dry weight is 3 lbs 2 oz coming it a bit less than the original setup the difference mostly being in the day pack itself.

EDIT: I added some UHMWPE cord and neon fabric markers later.

 

Would you consider throwing in an Apple AirTag or Tile in case a future theft occurs you possibly could recover it?

 

I’m curious to see how AirTag and some of the alternatives pan out. It’s not clear how useful they will be for recovering stolen goods since I suspect criminals will ditch anything that might contain a hidden tag but precisely because of that they might be useful for recovering the low value things they probably ditch quickly and nearby.

The missing feature for me on AirTag is an alert when an item is not moving with you anymore. I’ve left a few thousand dollars of gear in a pack behind at restaurants and such before and fortunately the staff has found and kept them safe for me until I return. It would be better if I got an alert shortly after pulling out of the parking lot. One time I drove more than an hour before realizing I’d left my pack behind - that was painful. Chipolo actually has this feature and they are suppose to release new tags and apps that use the more extensive Apple network soon so that may be what I go for.

 

$199 ZOLEO Satellite Communicator – Two-Way Global SMS Text Messenger & Email, Emergency SOS Alerting, Check-in & GPS Location – Android iOS Smartphone Accessory

Amazon.com: ZOLEO Satellite Communicator – Two-Way Global SMS Text Messenger & Email, Emergency SOS Alerting, Check-in & GPS Location – Android iOS Smartphone Accessory: GPS & Navigation

thoughts?

 

It is Iridium based which I consider good but having looked at the features and the reviews I'm not sure I see the advantage over the InReach Mini which seems to be able to do all the same things while coming in smaller, lighter and having a display for stand alone operation as well as having a lower monthly fee for the most basic use. As far as Iridium implementation goes both of them use the Iridium 9603 SBD Modem so really they should perform just about equally from the RF side of things.

The details probably come down to how you use it so I'll describe how I use my InReach and why the Zoleo wouldn't work as well for me.

Preset Messages

My main use for InReach is sending check in messages indicating that I'm OK and passing some status as to the level of oversight I'd like from whomever is watching me. InReach allows you to setup three "preset" messages which you can send an unlimited number of times even on the cheapest basic plan ($12/month). Almost all of my messages sent are these presets and are:

• I am with my vehicle and OK, notify SAR if you don't hear from me in 24 hours
• I am hiking and OK, notify SAR if you don't hear from me by 9PM local
• I am hiking and OK but doing something tricky, notify SAR if you don't hear from me within 1 hour

I use that last one if I'm doing something with a fall hazard that might leave me unconscious. All these messages can be sent very easily from the device itself without needing to connect my phone to it.

In comparison the Zoleo has only one "check in" message which is much more restricted than InReach and while I think it is suppose to be unlimited use I can't find anything to that effect and I see an Amazon review claiming otherwise. So Zoleo at least for me doesn't work as well for my most common use.

Text Messages

For InReach you can also send arbitrary text messages which I do rarely. You can do these directly from the device but it is quite fussy so usually I'll connect to my phone to send such messages through a Garmin app. Recipients can only reply to you via an InReach web interface that is linked in the text they receive (i.e. they can't just reply directly to your text) which on the one hand is a burden but on the other makes it impossible to get text spam on your device. The lowest cost plan ($12/month) includes just 10 texts per month but you can send additional texts for $0.50.

Zoleo seems to try to make the whole texting thing seem a bit more seamless by providing a SMS number but if I'm reading things correctly you still end up with an app involved. Their basic plan is more expensive ($25/month) but includes 25 messages while additional messages cost the same as InReach's basic plan ($0.50 per message). There are a lot of complaints about never knowing how many satellite messages you've actually used (compared with it having used your phone's cellular or WiFi connection).

Emergency Messages

As far as I can tell both are going to connect you to SAR via Iridium so should be similar reliability. I do like that with InReach that I can be sending replies directly from the device even if that is fussy rather than having to connect the phone but this is probably a minor point.

Other Concerns

The Zoleo Amazon reviews seem weird to me. Some of them have a real "influencer" vibe to me which makes me wonder how many are sponsored. A number of folks seem to think the reduced price of the device is quickly eaten away by monthly and per message fees on the lowest tier plan. Near as I can tell the "unlimited" plans from InReach in Zoleo are the same price so maybe in that case you still do get the cost savings of the Zoleo device.

As I've said elsewhere the InReach Mini isn't perfect - I find its GPS implementation poor but you can tell it to send messages without GPS if you know to do that. I don't have a good read on the Zoleo and it seems to have a much smaller install base to evaluate from reviews. It seems to be trying to solve a problem different than I am trying to solve (I have no need or desire for "seamless connectivity") and from some of the reviews it seems like it is a little hacked but it is always hard to tell what might just be user error.

It is good to see more and more options out there! I like a competitive market.