Altimeter watches: Made obsolete by the GPS sport watch?

For over a decade I wore daily an altimeter watch like the Suunto Core, also known as an ABC watch because most models feature a barometer and compass, too. My favorite was the now-discontinued Highgear Summit, which had the three basic functions, plus a stopwatch with 100-lap memory, easily navigable screens, oversized type, and quick-glance bar charts.

The Highgear Summit reading 101 degrees on the Pacific Crest Trail in northern California, July 2006.

The Highgear Summit reading 101 degrees on the Pacific Crest Trail in northern California, July 2006.

About three years ago I received a GPS sport watch, the Suunto Ambit2 (long-term review). I quickly realized that the Ambit was a revolutionary upgrade for running, and began to use it on all of my runs.

My decade-long custom of backpacking with an altimeter watch was slower to change. “Why do I need all of that data while hiking,” I skeptically asked. But after a few trips with the Ambit, my conclusion was the same: it’s a game-changing device. With only two minor qualifiers, the ABC watch has been made completely obsolete by the the GPS sport watch.

Functions of an ABC watch

For hiking and backpacking, an ABC watch has four useful features.

1. Timepiece

Using the clock, I would set an alarm, schedule my day, coordinate plans with group members, and dead-reckon.

2. Altimeter

With this data point, I could rule out false summits, and pinpoint my location by cross-referencing my altitude with another known landmark like a trail or creek confluence.

3. Barometer

The barometric pressure indicated the arrival or departure of weather systems. Based on this “forecast” I sometimes changed plans, like by going over a pass late in the day so that I would be on the other side when the storm finally arrived.

When I see the barometric pressure drop quickly, I know that a storm will probably arrive soon and I may change my plans.

When I see the barometric pressure drop quickly, I know that a storm will probably arrive soon and I may change my plans.

4. Compass

For extensive navigation, I prefer a high quality baseplate compass like the Suunto M-3G Global (long-term review). But with a digital compass I can roughly orient a map and find or transfer bearings, which sometimes is good enough.

The new class: GPS sport watches

Select GPS sport watches like the Suunto Ambit3 Peak feature the same hardware as a standard ABC watch: timepiece, altimeter, barometer, and compass.

But in addition, they have a GPS antenna and accelerometer, and are compatible with accessories like heart rate monitors and power meters via ANT or Bluetooth.

Select GPS sport watches like the Suunto Ambit Peak offer the same features as an ABC watch, and much more. For example, they can measure distance and pace via GPS between two points.

Select GPS sport watches like the Suunto Ambit Peak offer the same features as an ABC watch, and much more. For example, they can measure distance and pace via GPS between two points.

Because of this additional hardware — and the software and memory storage necessary to run it — a GPS sport watch is much more powerful than an ABC watch. It can:

  • Auto dead-reckon, by calculating the distance traveled from a trailhead or camp, or a more recent landmark like a junction;
  • Display current and average hiking speed;
  • Measure cumulative vertical gain and loss, which I have found to be the limiting factor when hiking high routes (read #3 for an explanation);
  • Perform basic GPS functions, like showing its coordinates, storing waypoints, and navigating to a pre-programmed landmark; and,
  • Create a GPX track of a route that can be shared or published later, as shown in the map below using the track of a day-hike I did in Rocky Mountain National Park in October.

These features are very useful for hiking and backpacking, as well as endurance sports like running, cycling, swimming, and Nordic skiing. Also, by uploading the data to Strava, I took my training analysis to the next level.

A final perk of GPS sport watches is that the displays are customizable. View my preferred screen settings for hiking and backpacking.

Most suitable GPS watches for hiking and backpacking

You may have noticed my earlier comment that only select GPS watches are full replacements for ABC watches. These four are:

  • Suunto Ambit3 Peak
  • Suunto Ambit3 Vertical
  • Suunto Traverse
  • Garmin Fenix 3

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I have been extremely pleased with my Suunto Ambit2, and cannot imagine a compelling reason to go with anything but a Suunto. For an explanation of the functional differences between the Suunto models, read this post.

GPS sport watch not listed above may not be a full replacement for an ABC watch. For example, the Suunto Ambit3 Run uses GPS to determine its altitude, not a barometer. So it offers no weather forecasting, and more importantly it cannot accurately track vertical change unless the GPS interval is set to 1 second; at 5- or 60-sec intervals the watch misses too much.

Maybe not completely obsolete

This post could be a few years ahead of itself. There are two reasons why you might still hold onto your ABC watch, or purchase one instead of a GPS sport watch.


The retail price of the Suunto Ambit3 Peak — which would be my recommendation — is $500. But for months I have seen it on sale for $300 or less: on Amazon and now at REI (Nepal Edition only). This is less than the retail cost of the ABC-only Suunto Core or newer Core Crush.

But ABC watches are on sale, too: $200 on Amazon for the Core, way below its $320 retail, and even less for the Casio Pathfinder and Casio ProTrek, which make my head want to explode when I simply look at them.

Are the extra features worth the extra money? They are for me, but YMMV.

Battery life

The CR2023 battery on the Suunto Core lasts about a year. The longest lasting GPS sport watch, the Ambit3 Peak, runs for 200 hours when set to 60-second GPS pings. View the battery life of popular GPS watches.

If you don’t want to worry about batteries, an ABC watch might be better for you. But 200 hours is a long time — the watch can run for 10 hours a day for nearly three weeks without a recharge. Most of my trips are long over by then. And in the unlikely event that I go on another thru-hike, I’ll probably have a battery bank like the Anker PowerCore+ mini to charge my phone and DeLorme inReach anyway. To charge my watch as well, I would need to carry just another 1-oz cable.

Your turn: Agree or disagree? If you own a GPS sport watch, do you find it as useful as I do?

Disclosure. I strive to offer field-tested and trustworthy information, insights, and advice. I have no financial affiliations with or interests in any brands or products, and I do not publish sponsored content

This website is supported by affiliate marketing, whereby for referral traffic I receive a small commission from select vendors like Amazon or REI, at no cost to the reader. As an Amazon Associate I earn from qualifying purchases.

Posted in on December 3, 2016
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  1. Lagrandeimage on December 3, 2016 at 5:34 pm

    Hello Andrew,

    Nice review as always.

    I bought a Suunto Core three years ago and was very satisfied with it until this year. It started getting fog issues after dips in the swimming pool. It even stopped functionning and I had to leave it in the sun to dry several times. I realized this came after I changed the battery several months before.

    I tried several times to really screw it tight but nothing changed. It is still usable but I would have to take it off if I want to take a dip in a river during a hike;

    After looking on the Internet, it seems I am not the only one with this issue. So I am having mixed feelings. One hand I like Suunto watches and your review strenghtens that feeling but on the other hand I am a bit pissed having bought a relatively pricey watch that just does not guarantee water resistance in a few feet of water.

    Ever had water resistant issues or heard of them for Suunto’s?

    • Andrew Skurka on December 3, 2016 at 5:42 pm

      I never had a water-resistance issue with my old Core, and it was submerged many times. But I can see it happening due to the user-replaceable battery. If that seal is not perfect, the internal electronics will be vulnerable.

      In any case, this sounds like a warranty issue. Not sure where you bought it, but I would bring it back. It should not be failing if you simply go for a swim with it. Suunto has the technology to waterproof its watches, from its diving line.

      The Ambit battery is not user-replaceable, but rechargable. Again, my watch has gone for multiple swims, and I’ve never had an issue.

    • Laina Barrett on July 8, 2018 at 4:50 pm

      Aren’t there tiny gaskets in any degree of water resistant watch, that periodically have to be replaced. And bery precisely. Especially any time case is open??

  2. Chris Oertle on December 4, 2016 at 10:15 am

    Great and informative article, Andrew (as always).

    I think one thing to consider is the audience, background, and reason for using the technology. I’m a Marine and naturally lean towards a more basic approach, relying primarily on strong land navigation through the use of terrain association and good compass skills. Although I haven’t done the long distance thru-hikes like you I spend most of my time off trail in the Wyoming/Montana Rocky Mountains and have had little need for such tools.

    I have a few needs/tools I use as it relates to this topic: time, alarm(s), compass, barometer, and power. My biggest requirement was solar power because I despise the dying battery issue. It would always happen when I needed technology so that became my primary requirement.

    Therefore, I have used ABC watches for three primary reasons. The first is that I have always worn a watch, feeling quite naked without one (habit vs. need is TBD). And secondly, I have utilized the compass function a great deal when in a thick canopy or significant cloud cover where line of site is rendered useless. Understanding basic cardinal directions with a good topo map has always served me perfectly – even when in the back country like the Thorofare in between YNP and TNP. And thirdly, I use the barometer a fair amount as a “loose” predictor of the weather.

    That led me to the clunky and mil-tech appearing Pathfinders for years because they were the only with solar power. About a year ago I changed to the Tissot Men’s T0914204405100 T-Touch Expert Solar which allows me to have one timepiece I can wear in the office, travel, and outdoors.

    I now have all the functionality I need with a tool not reduced simply to an outdoor tool – I wear it everyday and in every situation. I think the altimeter function has always been a novelty for me making it superfluous (and me an oddity in the ABC community). I certainly see the appeal of the GPS watches and the technology you use for the outdoor enthusiast wanting to track, compare, and improve technique. But for me and my needs this seems to hit every requirement in all situations. That and I really dig analog vs. digital!

  3. Brad R. on December 4, 2016 at 6:26 pm

    I have always thought of GPS watches as a tool for done in a day activities, mostly due to battery life, but maybe I am wrong as 200 hours would be enough for many of my trips. Does that mean, the watch is off at night? I use the watch, thermometer, and occasionally the alarm at night so I prefer something that I don’t have to turn off completely, but obviously the GPS wouldn’t be needed.

    I don’t normally carry a GPS, but did bring my iPhone with Gaia GPS on my WRR High Route trip this summer and it still had over 50% battery Since I think you also bring your phone, how to the two compare, do the complement/supplement each other? Are they redundant? I would think navigating from a watch would be a pain in the butt.

    I am planning to do the Southern Traverse in Wrangell St Elias next summer and think it will take me 12 days so even then the 200 hour limit wouldn’t be enough, but most of my trips are a week or less.

    Currently I use a Highgear altimeter watch that I got on Steap and Cheap for $55 in 2005. It has always done everything I want to do, but eventually it will die I am sure.

    • Andrew Skurka on December 5, 2016 at 8:18 am

      When the GPS is not running, the watch still has three screens: time (with date, day of week, or battery power), barometer or altimeter (with temperature), and digital compass. The alarm will still function.

      The Ambit3 Peak will supposedly go 30 days without a recharge if the GPS is not turned on, but I feel like it’s probably even longer than that.

      A GPS watch and Gaia are complementary, not substitutes. The watch is good for recording your track, cumulative distance, distance since last landmark, and cumulative vertical; it is also useful for its altimeter and barometer. But if you really need to “find yourself,” you want a GPS with a display on it. Also, any landmarks used to “nav to” must be stored beforehand in the Ambit2 (with the Ambit3, which has Blueooth, you might be able to do this with your phone, though I’m not sure), whereas in Gaia you can create them in the field very easily.

  4. Paul on December 5, 2016 at 6:50 am

    Andrew, have you found any distance measurement accuracy issues under tree cover? Any issues with it’s ability to maintain the signal, and its impact on battery life?

    Much of my running is on trails with moderate tree cover. In the past I’ve used my smartphones GPS to track these distances, but I’ve never checked it for accuracy. I remember seeing you post that it was pretty accurate during the Denver marathon … but I was wondering how it fared in the woods.

    I’ve been considering one of these since you originally posted about a few years back. The price tag has always been tough for me to stomach. You demonstrating its usefulness (in multiple arenas) has been helpful to me! Thanks for continuing to provide informative content.

    • Andrew Skurka on December 5, 2016 at 7:48 am

      Accuracy depends on the watch. You might want to read this, He has not tested all of the watches out there, but enough to get a sense for the accuracy of brands and models. His quantitative assessment mirrors my experience with the Ambit2: it’s pretty accurate, though probably not on par with handheld GPS with a more powerful antenna.

      I’m willing to overlook some degree of inaccuracy because it is so convenient (relative to, say, running with a handheld GPS). The only instances when I notice major inaccuracies is when I have the watch set to 60-sec GPS pings, there is some electricity in the air, and I’m not moving much or at all. For example, look at this GPS track, Notice the erratic behavior as I was sitting at Grouse Lake waiting out a thunderstorm.

      • Paul on December 5, 2016 at 8:05 am

        Excellent! If I could upload a screenshot here, you’d see me finish reading that EXACT article! Great to know your experience correlates to his testing.

      • Bob S. on December 6, 2016 at 7:21 pm

        Hi Andrew, I’m a cyclist and use a speed/cadence sensor so I’m not concerned about GPS accuracy as long the GPS records my track within reasonable expectations.

        I was wondering if you train with a foot pod and if they deliver consistent and accurate results the way speed/cadence sensors on bicycles do or if changing your pace/stride will mess up the measurements. Does the accelerometer do a good job compensating for any changes?

        I have no idea how foot pods work but with a speed/cadence sensor, the measurement is straightforward and accurate as long as the correct tire size is used when calibrating the receiver.

        • Andrew Skurka on December 7, 2016 at 8:56 pm

          I don’t use a foot pod, as I’ve always been happy enough with the accuracy of the GPS.

          Foot pods are really useful for running indoors, however, maybe I will have to get one for the winter if my wife gets that family membership she is talking about.

  5. Bob S. on December 6, 2016 at 6:27 pm

    I’ve been using a Suunto X9i GPS watch since 2005. It worked great as an ABC watch but the GPS functions were never very good and the battery life with the GPS activated was about 4 to 6 hours (when my watch was new). Suunto took a fair amount of heat for this because good portable USB chargers were not available until several years after the Suunto X9 was introduced and there were a lot of unhappy people with $500 GPS watches that were only good for day use. Suunto tried to mitigate the problem with a ridiculous wearable 9 volt charger you could attach to the watch. I would have to guess this is why Suunto never mentioned the X9 series on their website’s product history page.

    Eleven years later, my X9i still works as a decent ABC watch and will run for a month before it needs to be recharged. With the GPS activated, it will run about 2 hours before shutting down.

    Last spring the wrist strap broke and Suunto said they no longer supported the X9 but could replace the wrist strap for $40. The battery could not be replaced but Suunto offered some sort of swap-out but did not give any details.

    I decided to replace my GPS watch with the expectation that a new watch would be little more than a gimmick like my old watch was. I was wrong, the high-end GPS watches on the market today are almost as accurate as hand-held GPS units and it’s much more convenient to have GPS information on your wrist than strapped to your belt or pack.

    My new new watch is great but think I’ll get the wrist strap replaced on my old friend.

  6. Kevin M on December 9, 2016 at 10:05 pm

    I’ve had a Suunto Core for 4-5 years, I think. I’ve struggled with the bezel (CA glued back on) and the buttons, and even tore into it to repair the “-” button not working (don’t sneeze! all the screws are microscopic). Once, it freaked out and thought it was 99C and we were at 10000+ meters and stayed that way for a week. Friends have all had problems with the straps degrading, especially those that swim in pools. I liked that the alarm on the Core would wake me up backpacking and I could have it on long enough for a trip, it’s definitely been great for that and day to day watch duties.

    I’ve also had a Garmin 910XT multisport watch – true “multisport” watches won’t run long enough for a long trip. It has held up far better than the Core over about the same time period (less daily use), despite now being very antiquated compared to the modern stuff.

    I’m concerned about the Suunto watch robustness compared to a Fenix, with this anecdotal experience. 3 questions/thoughts – any other bad stories or good stores about Ambit durability? It’s not the Core, but seems similar. And it seems like 200hrs of tracking vs 50hrs is hardly comparable for trips of significant length, right? Did you consider a Fenix?

    • Andrew Skurka on December 10, 2016 at 8:15 am

      According to Movescount, which is Suunto’s online platform for keeping activity data, I have used my Ambit2 for 894 “moves,” which could mean a 2-mile run to the grocery store, a 100-mile ultra marathon, or long day of scrambling on granite in Colorado’s Front Range or the High Sierra.

      My only complaint about the durability is that the most commonly used button, the start/stop on the upper-right side, started getting sticky about 18 months ago. Submerging it in water solves the problem.

      The battery seems to hold almost the same charge it did when new. At the end of a 23.5-hour ultra this summer, the Silverheels 100, my watch had a 5% charge left. Per Suunto it should last 24 hours at the 5-second GPS ping interval. So it was on track for that. And this watch has been recharged hundreds of times.

      The face and bezel have a few scratches, but I would have thought there would be many more. And I don’t even have the Sapphire glass version. Took this photo just for this comment thread:

      Ambit face

      • Kevin M on December 17, 2016 at 7:04 pm

        Thanks! My Core is considerably more haggard, but similarly very few scratches on the non-sapphire face. I’ll be happy to ditch the double watch for a single.

        I had an older Garmin die 8 hours into a 9.5 hour race…kind of heartbreaking. Glad your battery didn’t give out on Silverheels!

        So the 200hr capability tipped you in favor of the Suunto vs the Fenix? I’m in the Garmin “ecosystem” now, so that seems to be the strongest reason to move from Garmin Connect to Moves Count.

        • Andrew Skurka on December 18, 2016 at 9:18 am

          I’ve heard very mixed reviews about the battery life of the Fenix, whereas the Suunto estimates have proven to be very accurate. Also, the recommended setting for longer battery life, UltraTrac, is reviewed poorly, with data inaccuracies and uncertain battery life estimates.

          I auto-transfer all of my Ambit data to Strava. The data stays in Movescount, too. Strava is not as powerful as other platforms like TrainingPeaks (at least the free service is not) but it’s enough for me. Plus, I like being able to see my times compared to others, and the social aspect of it.

          • Bob S. on January 4, 2017 at 7:02 pm

            The Garmin fēnix 5 was announced today along with the new inReach SE+ and inReach Explorer+

            Perhaps it’s time to trade up that old Ambit2 of yours?

          • Kevin M on January 5, 2017 at 1:24 pm

          • Andrew Skurka on January 5, 2017 at 3:16 pm

            I have a press appt with Suunto next week at Outdoor Retailer to discuss this product. I’ll report back. Fingers crossed, I’m hoping that they give me one for testing.

        • Kevin Moynihan on September 21, 2017 at 8:11 pm

          I pulled the trigger on a Fenix 5, finally. It has enough day to day features for training that I liked over the Suunto. Nonetheless, I wanted to use it for backpacking, so I have some info to report for this thread:

          We just did 5 days in the Wind River range. The first day I used Ultratrac, which was a battery sipper but off by almost 50% on mileage (over estimate). The more you stop and the slower you are, the worse the error is… not great for backpacking. The error builds up that way because it reacquires satellites for every saved data point, so you get a large (100ft) random error for each ping. Used about 7% of the battery for that day. The rest of the days, I used the normal mode GPS mode, without GLONASS, and it was far more accurate (within .1s of a mile, might have been map error) which ate about 12%-15% battery/day, logging 5-8 hours a day.

          I did also have our route saved, so a few times I was able to pull it up momentarily and verify our direction. Definitely higher resolution than a map. I carry a decent camera too, so I could have left a smart phone in the car for this trip.

          Overall, ultratrac was most disappointing. Basically useless. However, the watch is pretty sweet and the battery with all the lights and functions off except GPS recording seemed to get better than the 24 hr stated life, and it can be powered off during the evenings as well as recharged on the trail.

          • Andrew Skurka on September 21, 2017 at 10:34 pm

            Thanks for sharing your experience.

  7. Brad R on January 5, 2017 at 3:25 pm

    That new Suunto watch looks very nice though not cheap. The ability to use the wrist HR monitor in everyday activities and add a chest HR monitor when better accuracy is needed will be nice. I wonder if the battery is as good as the Ambit 3.

  8. Chris on January 29, 2017 at 9:17 pm

    I have also found that my Ambit2 is replacing my Core. However, I have found the vertical gain and loss (especially while ski touring) to be often inaccurate. I’ve compared it to my partners watches as well as the value determined from the GPX file on a mapping program. It seems the vertical gain and loss is commonly overestimated by 10-20%.

    I’ve tried a number of different settings but haven’t found anything that fixes it.

    Have you experienced anything similar?


    • Andrew Skurka on January 29, 2017 at 9:24 pm

      Mine is consistent, which in some respects is just as important as accurate.

      When I upload my data to Strava, I usually get a bit more mileage and vert than for which the watch gave me credit.

      Do you have the Ambit2 (Peak) or the Run or Sport? The latter two watches have GPS-based altitude, which is less reliable.

      • Chris on January 30, 2017 at 6:57 am

        Thanks for the reply. I have the Ambit2 with barometer. I’ve tried it with the FuseAlti feature on and off and it doesn’t seem to help.

        For ski touring the ascent/descent is the most important measure of the day so I’m bummed that it seems off. I’ll keep playing with the settings and see what I can figure out.

  9. Mark Fowler on September 18, 2017 at 1:48 am

    Hi Andrew

    As an “old fart” I don’t feel the benefits of the gps watches really match my needs. I find most of my navigation requirements are met with a phone that I am likely to be carrying anyway and it has a nice 5.5″ screen, the Avenza app and Geo-pdf maps although I always have a paper map and a compass in the pack.

    I still have a Suunto Vector (precursor to the Core) which I bought in 2004 so 13 year old. I buy it a new battery every Christmas and apart from a new strap it still going strong.

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