njkayaker

Hyperbole.

Don't get why people on expensive boats would do this. I guess because it's just easier. If it's submerged rocks, I could see people not paying enough attention.

Yes. I do a lot of OSM updates so being skeptical is routine for me. I try to impart this when I teach people how to use them.

Being in the slot canyon should be enough tell people where they are. I was in one situation where the GPS though I was rotating while moving.

Seattle Forrest

​​​​​​As long as we're clarifying the obvious, I guess it's also worth saying "this doesn't happen for me" doesn't mean "I don't believe you," it means "something weird is going on and it's like there's some hidden variable."

JohnJ80

It's not hard to get caught out in bad weather unexpectedly. Anything that reduces visibility can be an issue - fog, rain, night etc... Usually, it's pretty good practice to keep a dead reckoning plot going as well as an electronic one and continually cross check them. Not doing that is when you get in trouble. And when you get in trouble, you're really in trouble and you often don't know which way to go. Pick the wrong one, and you're up on the rocks.

I've seen GPS systems show me that I'm on land when I'm not, probably because I'm behind a high headland and don't have a good view of the satellite constellation. In that case, the GPS gets me in trouble but the DR plot saves me. I've also sailed in a straight line over a probable magnetic iron deposit at night trying to make the finish line and watched the compass do a 360 in about 50 yards (happens often in some geographies). So if you're not skeptical while navigating, you're going to get in trouble at some point. Then there is the whole subject of equipment failures....

I'm sure you already know this, but it's not just slot canyons - serious tree cover, riding on city streets with high buildings on both sides, etc... There are innumerable geographies that have reception issues for GPS. It's not a particularly strong signal and, in point of fact, it's relatively easy to have interference with it both physically and electrically (RF). Pays to be skeptical. GPS is better than what we had (LORAN etc...) but it's not infallible and it's even not all that good but it works well with other tech that can cross check it (i.e. cellular triangulation etc..).

njkayaker

This doesn't seem very relevant to cyclists on roads. The issues with use on water are very different (and much more critical).

I can see people on water having "absolute faith" in a GPS. I doubt that cyclists (especially on roads) ever do (except, maybe, in weird rare cases).

There are stories of drivers driving into "lakes" because their "GPS told them too" but that doesn't seem very common considering the high-level of use. These people might drive into lakes without GPS. I wonder if this rare thing is even less common for cyclists.

Sure, this happens but it doesn't seem that common (I rarely see it) or big enough to "cause problems". Seems the biggest issue is missing a turn (but that isn't generally hard to notice).

When I'm using a Garmin for navigation, I have an eye on the map. I usually know about turns before they are announced and can see that I've missed any turns. Many people just rely on the turn announcements, which has issues (easy to miss, can be confusing. sometimes aren't shown when you expect them). In the rare cases where the GPS shows me off the road, it's easy enough to see the road I'm on (that is, this isn't really ever a problem if you look at the map).

Where it's being used matters. LORAN suggests you are talking about boats, which isn't that relevant to cyclists. (One will have to be much more careful/skeptical on water.)

Nothing is "infallible" but, from what I've seen over thousands of miles (cycling and driving), it works well (much, much better than "not all that good").

Steve B.

There was a story many years back of a Lear jet that disappeared around Christmas time while attempting to fly into Lebanon, NH to PU a family to fly them on vacation. Plane never made it and it was a good 2 years before they found it NE of Lebanon in deep woods on a hillside. The NTSB investigation indicated the pilots were relying too much on a newly installed GPS that they had very little familiarity with in flight conditions, they subsequently lost track of position and altitude, flew into a mountain at 250 MPH. And there have been countless stories of motorists that drive up an Oregon dirt road (or something similar) into snow and get stuck, while following the directions Google Maps is giving them. A lot of people have no idea how it all works and why it sometimes doesn't, including pilots, who should know better.

JohnJ80

well, we apparently differ on the definition of what “good” and “reliable” and “well” are (as if that really ever matters). YMMV. Our experiences differ - mine also over thousands of miles of cycling and driving.

Badger6

Civilian GPS sets are accurate...enough. I'd never do anything requiring precision with any of them. Not even the new 1040 (that is hands down the best non-military receiver I've ever used). As for slot canyons. You haven't lived until you've been under murderous machine gun and rocket propelled grenade fire in the bottom of a valley in Paktia Province, Afghanistan, and the mountains stretch above you 2000+m and the only help you've got are two B52s at 38k AGL and they need really specific grids to get the JDAMs to where you need them, and being off 10m means they hit the valley walls 200m above the dudes trying to kill you. Forgive me, everyone, if I think these complaints about "lag" and minor positional deviations are trivial.

Our experiences definitely differ...though I'm guessing that dragging your hull over submerged rocks is awfully sporty.

njkayaker

It works fine for many millions of drivers and cyclists.

It's not clear what sort of issues you have while cycling or driving (we only have not quite relevant examples when sailing), but they don't seem common at all.

njkayaker

All these stories are still relatively rare. In a pool of billions of uses.

The fact that a relatively small number of people still get into trouble is not an indication of it being "unreliable".

People manage to crash airplanes and drive up dirt roads without GPS. It wouldn't surprise me that GPS gave people more confidence to get into trouble but it's still really rare.

These aren’t even “GPS problems”. The “dirt road proble” might be a map problem but we really don’t know (it could be a “person ignoring the road they are in is dirt problem “).

njkayaker

For normal usage, they are trivial. They don't cause anywhere near the problems some people are claiming.

JohnJ80

now we’re definitely exploring the range of hyperbole (to the point of being ridiculous) when it comes to GPS accuracy and error when cycling. If it gets to the point where I’m expected to call in air strikes while cycling, then I’m probably going to find something else to do instead. 🙄 But, hey, that’s just me.

here’s a succinct discussion of gps accuracy and where the error comes from with a nice clear diagram of how geography can impact accuracy and error. Even without any imagination, it’s easy to see where and how this can be a problem for a cyclist and why relying on GPS for speed and distance in the short run can lead to numbers that make no sense or in navigational guidance that is wrong. When you add in maps and the underlying routing information that adds a lot more inaccuracy.

If having that happen to you doesn’t matter (as it doesn’t for many people) then that’s fine too. If you ride in wide open spaces, it will likely never be an issue. But if it does matter to you, here’s why it happens.

For me, it matters. I ride in areas that are either mountainous, hilly, or heavily forested (or some combination of the three). In those cases speed numbers (especially in trees) are often wildly inaccurate for extended periods and map position is sometimes funny for its inaccuracy. I don’t like that and it’s just a lot easier to solve it with a speed sensor to help the computer out and to be skeptical of what I see on the map.

as always, YMMV.

Seattle Forrest

njkayaker

"Commercial air travel is dangerous because a few commercial airplanes crash."

How does one example invalidate all the millions of times it works well enough?

It seems like you think I said it was perfect.

You also have no idea what's behind this odd case.

Seattle Forrest

Take a deep breath and count to ten. Repeat after me: "it's going to be ok." We don't want to see you stroke out.

Badger6

Completely agree, that’s why now I live a life that is much less exciting, if you will.

Personal use: I ride in mountains, I ride in urban canyons, I ride in forests, I ride next to canals, I ride across fields…I’m slightly annoyed when I note that my displayed position has drifted. I’m slightly annoyed when there is lag, like when changing direction of travel at an intersection, or a curve, roundabout, etc. I am keenly aware how GPS works, but in the end, it’s not a big deal if it is not always within 3m accuracy when riding a bike. I can see where it is a huge deal piloting a ship or plane, and of course in the case of the personally lived example from 2009 I provided above. My 1030 (not the plus) was good enough for cycling, and never was the cause of a bad ride. The 1040 I now own is much more precise in terms of positioning. But, at the end of the day, my ability to enjoy a bike ride, commute to work, or run to the bakery is unaffected by the accuracy or lag of the device recording the ride on the handlebars.

One exception, I was in Strava looking at my personal heat map recently, and remembered a ride where I was continually about 10-15m to the left of my actual track, it was weird to see a single line on train tracks, then later in the middle of a canal, and then finally in a major highway. I remembered that ride, the segments were wonky as hell, and a multitude of them didn’t even show up, but the mileage counted, so in the end...

Seattle Forrest

Garmin changed chip providers for the current generation of their products. My Fenix 7X is far and away the best GPS receiver I've had. It's better than in my phone or in the 1030+. Your 1040 probably has the same chip.

Are you using multi band?

Badger6

Yes. Massive improvements in track results, specifically in the “hard” environments. My 1030 was pretty good in the open, and acceptable in the city and forest, but was challenged at times. The 1040 so far has been much more precise.

Seattle Forrest

I guess there's been a geomagnetic storm recently and a lot of GPS units have been going crazy. Lot of people are reporting offset tracks.

Seattle Forrest

I'm seeing excellent results whether I use multiband or not. I guess there isn't much reason to turn it off in an Edge, it drains the battery about twice as fast as "all systems" GPS though and there are fewer times you want to charge a watch. But my hunch is it might just be the new chip is excellent.

Badger6

I think this is the case, functionally speaking, both in terms of capability (multi-band and multi-system) and performance.

njkayaker

Trollish. On top of a dumb comment.

Seattle Forrest

Getting a fix is immediate. Even when it's hundreds of miles from the last place I used it.

Badger6

I haven’t had the chance to do that with the 1040 yet. But, that’ll be quite welcome. The 1030 always seemed to take a bit of time to get a stable fix whenever I traveled somewhere to ride, whether it was an hour away or several hundred kms away.

M Rose

I was going to mention we had a trucker disappear for about 2 weeks due to his truck’s GPS system malfunctioning and sending him up a road where I wouldn’t even take my worst 4X4 in the heat of summer. He ended up getting stuck in the mud and snow about 20 miles outside of town and walked out on the very road system the GPS said to take. The Dispatch GPS showed the truck 60 miles in the opposite direction so we (SAR) we’re looking for him in the complete wrong area.