GPS recommendation

[Bob Gross]

"would you recommend the Garmin Foretrex 301"

For your purpose, absolutely not!

A Foretrex 301 is not a mapping receiver. The product images show its display, and it shows a track log with no underlying topo map. For geocaching, that is not what you want. You got lured to the 301 by its cheap price.

–B.G.–

[d k]

Yes, that would be me…

I should probably consult with someone in my hiking group who seems to be knowledgeable about GPS. Then maybe I'll have some questions for you.

[Tohru Ohnuki]

"I know that cellphone should not be relied upon as navigation device, but i had no idea it would be this useless."

A lot of them require access to the cellular network to download the map images, unless you're running an app that uses pre-stored maps and you downloaded them in advance.

+1 on getting a small non-mapping GPS and using it in addition to a map and compass (you're always carrying those anyway right?) I like the trick of downloading the USGS topo maps and printing the areas i'm going into at 1:1 so that the UTM grid is the right size. Or buying the actual map if i'm covering a good fraction of it. I've also been finding recently that an altimeter is really useful…

[j lan]

I have had good experience with Backcountry Navigator for Android http://www.backcountrynavigator.com/

Where I live there is zero cell service, make sure you download all the tiles of the areas you are going to use it in before you head off grid. Provides tracking which can be overlayed on google when you get home.

Free to try $10 to buy, no cost for the map tiles!

[Chad Miller]

"would you recommend the Garmin Foretrex 301"

For your purpose, absolutely not!

A Foretrex 301 is not a mapping receiver. The product images show its display, and it shows a track log with no underlying topo map. For geocaching, that is not what you want. You got lured to the 301 by its cheap price.

–B.G.–

Actually I got lured to the 301 by another recommendation in this discussion and BPL. ;)

What GPS would you recommend for what I want to do with it? I'm all for quality and getting what I pay for so if it's coextensive I'll simply have to save up for it.

[Ben C]

What app were you using? I have had pretty good results.

[Bob Gross]

"While we were by Agnew Pass (close to Silver/June lakes in Mammoth) the GPS showed a "lock" and then showed that we were in the middle of Barstow, CA – which is only 250 miles away.'

Hey, it located you within the correct state, didn't it? Some receivers like that need cell service to assist the GPS operation, and maybe the last cell tower where it had a full conversation was in Barstow.

Don't take offense here, but there are too many people running around with a piece of technology and they really don't understand how it works, or how it fails, or what its limitations are, or how to optimize its performance. Whatever you intend to use for backcountry navigation, whether it is a dedicated GPS receiver, a cell phone with GPS, a map and compass, a sextant, moss on one side of a tree, or the stars… you really need to practice and learn with it until it works for you dependably. Only then can you depend on it in the backcountry. (RANT-OFF)

I've traveled around the wilderness trails in Yosemite National Park a lot, and I have run into people out on the trails who were trying to use a GPS receiver like a devining rod. They expected to be shown arrows on the display to tell them where to step next. It's just crazy.

Once many years ago, we were climbing a big peak in South America. I had my very first GPS receiver along, and it was one of the oldest, clunkiest, slowest GPS receivers that you could imagine. But I had practiced enough with it that I knew what to expect. When we reached the nearly-7000-meter summit, I set the receiver down on a rock to let it zero in its position, and it displayed an altitude that was only one meter off the official altitude. That was luck, but it was gratifying.

–B.G.–

[Jeremy and Angela]

I'll put in a recommendation for the Gaia GPS app, and second (third?) the advice on downloading the maps pre-trip and getting really familiar with your device.

I've seen odd mapping glitches on phones (my Blackberry in Beijing had Google Maps consistently shifted about a city block or two in one direction), but my iPhone 4 has been good as long as it had a GPS signal. I do lock out the SIM card when hiking, so the only data it sees are from the satellites.

Ed: for grammar, because data are plural.

[Bob Gross]

"What GPS would you recommend for what I want to do with it?"

I don't know. There are too many variables.

1. To start, look at Garmin only, since Garmin is the market leader by far. I will not say that Garmin is perfect, but overall Garmin tends to have more product offerings than anybody else, and they've worked good for me. Later on, if you think you have a Garmin model picked out, then you can compare that to one or two competitive brands. REI's web site, for example, I think has a comparison feature for some products that they sell.
2. For geocaching, I would think that you want a very portable unit that is small enough, but it has a relatively large display. Maybe you like to squint at microscopic displays, but I don't. I think you want a mapping receiver with a topo map database. If you had one with very good reception, that would be a plus. Newer models tend to have better reception than ones six years old. I think some models have other communication capabilities built in such as cellphone, bluetooth, and maybe something else. As some geocaching user what model they use, and why.
3. For ultralightweight backpacking, I would think that you want a very lightweight portable unit with a paper map for backup. For a few years, I used an ancient Magellan receiver, but it was horrendously slow and then it failed catastrophically, so I moved over to a Garmin GPS12XL in 1997. No mapping. I used it successfully for backpacking until about 2009. That's right. Twelve years of backpacking. Also, I used that one on my job when I taught GPS classes and helped customers install GPS fixed-station receivers. Then in 2009, it was borrowed for too long, and I purchased a Garmin Colorado that has mapping, but I leave it in my car. Finally and specifically for ultralightweight, I purchased a Garmin Geko 101 which operates on two AAA batteries. It has a pretty old design, but it weighs only 3 ounces. I carry it on backpacking trips, but I don't need to use it much. It is not a mapping receiver either, so I would never use it for geocaching. See what Garmin recommends for geocaching, and start there. See what Garmin recommends for backpacking.

The Geko is sort of like a very old version of a Foretrex, except the Foretrex is smaller. A friend of mine bought a Foretrex and used it for about one season of cross-country skiing, and then filed it away.

–B.G.–

[Joseph Reeves]

I use the GAIA GPS app on my iPhone when off the cell grid here in Southeast Alaska. I download the topo of the area before heading off the grid eliminating the sometimes confusing "you are here" spots when within cell coverage. It can be a battery burner, so we will carry a "real" gps on long kayaking trips, ut that's just to mark camps for the next run.

Compass and map beat all gps devices because they don't need batteries. And they are fun.

[Bob Gross]

"I've seen odd mapping glitches on phones (my Blackberry in Beijing had Google Maps consistently shifted about a city block or two in one direction), "

Yes, many devices like this have an accurate map database, but the registration of the map is consistently off by about a city block or two in one direction. It will show you driving off the Interstate highway and going parallel to the pavement by a block or two. That is frustrating. There are things that cause that, and some of them are user-correctable and some are not.

Refer to the topic: GPS Datum. Learn what that is and what it does.

Also read up on the topic: GPS Blunder. Learn what that is and what it can do to you.

If you understand how GPS works, you will find that when the receiver sees the multiple satellites, it determines a PVT solution. That means Position, Velocity, and Time. In all likelihood, it will determine two PVT solutions, and one makes sense and one does not. One will be within 300 miles of where it had its last fix, and it will be somewhere reasonably on or near the surface of the Earth. The nonsense solution may be too high in space, or going at some incredible velocity. Nearly all of the time, the receiver will guess which solution is nonsense and it discards it, so the only PVT solution that the user sees is the accurate one. However, once in a while, the real solution and the nonsense solution are moderately close to one another, and once in a great while, the receiver guesses wrong. This is called a GPS Blunder.

One day I backed my car out of my garage in Silicon Valley, and I gave the GPS receiver a moment to lock a position fix. Suddenly it displayed me traveling about 20 miles away, going at 400 miles per hour, and flying over the foothills. For the first five seconds, I stared at it in disbelief. Then I shut the receiver down, counted to ten, and then powered it up again. This time it displayed me about 30 miles away, still doing 350 miles per hour. Wow. So I shut it down again, counted to ten, and then powered it up again. This time it displayed me sitting about twenty feet from my garage and had zero speed. Ah-ha. It worked great the rest of the day.

These GPS Blunders used to happen maybe once per year, and it was purely a fluke of luck. I haven't seen so many lately, and I think that has to do with the maximum constellation of satellites being present nearly all the time now. In other words, the system is better now.

Additionally, if you happen to wander into an area of high radio-frequency fields, your GPS receiver might go squirrelly. I've been to many microwave radio sites, and the GPS would be crazy. I would leave the site, and the GPS straightened out immediately. I've been to places where I could stand at one spot, and GPS would fail. Then I could move five feet to the right, and it would work perfectly. This has to do with what we call RF Interference. Be on the lookout for anything that looks like a big microwave dish antenna. For this reason, you don't want to place a geocache near a microwave antenna, because maybe nobody will be able to find it.

–B.G.–

[John S.]

Agree with gridded map and Foretrex 301.

[Bob Gross]

If you are a backpacker trying to navigate along a standard trail, you shouldn't need anything except the roughest of printed maps, but preferably a topo map. It is good practice to bring along a compass and practice shooting bearings to try to triangulate your position along the trail. So, you shouldn't need GPS.

Now, where GPS starts to pay off is if you have an unexpected problem. For example, if you have fog that limits the trail visibility, that will be a problem because you can't sight far enough to find landmarks to shoot compass bearings. Or, nightfall. Then you can't see much of anything. If unexpected snow covers the trails, then they become difficult to follow. Something might force you off the trail, and then you are working cross-country.

Or, and this has happened, once in a while you will have a brain failure. Either you weren't paying close attention, or some trail was re-routed and you didn't know, or something else threw you off your navigational game. You might be able to study the map and figure out enough to operate on. However, GPS will likely be quicker and more accurate. Sometimes you are desperate to finish a trail before sundown. You could sit there and fool around with compass bearings until the coyotes howl, or you could just walk out directly with GPS.

So, I generally carry a GPS receiver just as a last resort.

–B.G.–

[Mike W]

…

[Bob Gross]

" What most people don't realize is that non-mapping GPS's don't allow you to "pan" across the screen. "

Except for the non-mapping units that do allow panning.

–B.G.–

[Mike W]

…

[Dale Wambaugh]

I'm not a GPS expert, but here are some of my experiences with them:

*They are great fun and can be very useful, but know how to use a map and compass and HAVE THEM. Using maps, compass and GPS together is great. Learning to navigate can be a useful (even lifesaving) addition to hiking and doesn't need to be an onerous burden. GPS records of trips are fun to keep, much like photos.

*Less expensive models are slower, some are REALLY slow.

*Sensitivity counts. If you are going in and out of thick overhead foliage you may lose your fix and the track you are trying to save; likewise in deep ravines and canyons– you need a good view of the sky.

*Battery life. If you have a modern color unit loaded with maps, a large screen and tracking all the time, it will use up a rechargeable battery too fast for my liking. Great for a not-too-long day hike, but not very practical for a multi-day trip. Those that use a few AA batteries may go longer and you can replace them as you go, but the feature set is smaller and they are slower, less sensitive, etc. Compromise, compromise….

*Maps. I have an older Garmin sTrex Legend that I can load maps on. It is monochrome and has a small screen, but having some sort of topo map capability is really a plus. Base maps without good detail don't tell you much more than what you already know– "I'm on the side of this mountain somewhere." You can get accurate coordinates from just about any GPS and transfer that to a paper map, for a good "you are here" fix and work out your route from there. That means having map and compass skills— and a clear fix on the satellites.

I basically use my GPS to verify my position as an accessory to a paper map— "how far is it to the lake?" I don't use a compass on a regular basis as I try to make sure I know where I am and where I'm headed. If I'm day hiking up a river valley, directions are fairly obvious. It is nice to take a bearing to identify a peak in the distance and so on. I wouldn't think of hiking without a decent compass and maps.

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