Suunto Core Extreme Review

Last November, after several months of indecision, I treated myself to a Suunto Core. I'd not worn a watch for several years, but I had a secret craving for a Suunto for some time - partially because of their stylish designs, but also because they hail from my adopted home of Finland.

The Suunto Core Extreme. Standard face, showing barometric trend (which appears to be uneventful).

Shortly after its initial release, the Core had a bad reputation for poor quality and software bugs. It was Suunto's first watch to me manufactured in China.  After checking some Suunto fanboy forums, I discovered that the current batches had resolved all the problematic issues. Spurred on by the Suunto-espousing elite, I succumbed to temptation, and had to make a choice between the seemingly hundreds of versions of the Core available.

I don't know whether they use pixies as arm models, but in many images, the military-style (Black/White/Orange) Cores with the rotating bezel appear to be huge. Perhaps this is intentional, but I didn't want to look like a dork walking around with a clock strapped to my wrist. Suunto had recently released a limited edition model of the Core - the Core Extreme - without the rotating bezel, which made the watch appear a little smaller (in reality, it is almost the same size). I decided to go for it. It was, you might say, time.

Compared to their main competition - Casio's Pathfinder watches - the Suunto Core is the epitome of minimalism. The Pathfinder looks like you are wearing Space Shuttle mission control on your wrist.

As I mentioned, Suunto make the Core in a confusing amount of shapes and forms, and at a startling array of price points rangling between €200 and €600.  However, the functionality and software of each Core model are exactly the same. The price differences are the result of the the different materials used to construct the strap and face. To me it seems a little ridiculous to pay several hundred euros more for a stainless steel face and strap, but this appears to be Suunto's sales strategy; to charge absurd amounts of money for non-functional aesthetics. The only useful difference between models is whether or not they have a rotating bezel, of which more later.

What does it do?

In addition to the standard chronograph-related functions (clock, timer, countdown etc.), it features an altimeter, barometer, thermometer, sunrise/sunset info, and digital compass. It is also able to log records of increasing/decreasing altitude and barometric pressure, and track bearings.

Unlike Suunto's other lines, the Core is not compatible with heart-rate monitors, and hence is not so relevant for hardcore trail-runners or other athletes. It's feature set is, however, well suited to backpacking. I wouldn't go so far as Suunto and claim that it's a wrist-top computer, but it certainly has a set of features that could be seen as useful in the wilderness.


Rather than dwell on the timey-wimey features of the Core, let's just say that it meets all the standard criteria: it has dual time zones, and all the stopwatch and countdown timer functions you might need to, I don't know, boil an egg or something. I find these functions of little use outside of measuring the boil time while homebrewing. If I ran, I might find them more useful, but I suspect that there are better tools available (such as Suunto or Polar heart rate monitor watches).

Perhaps the most useful time-related feature for hiking purposes is the sunrise/sunset calculator. To access this you must select the continent and city nearest your location, so it's not super-accurate - especially in higher latitudes - but it provides a helpful indication of how long you have left on the trail before it's headlamp time.

Current sunrise/sunset time for Minneapolis shown below time.

By far the worst aspect of the clock is the alarm. It's weedy. It wakes me up at home, but if you have your arm stuffed deep in your sleeping bag don't expect to be roused from slumber in a hurry. I don't find this a problem as I wake up with the dawn anyway (providing, of course, that I'm somewhere where there is a dawn).

Altimeter and Barometer

The "meat" of the Core - the features that differentiate it from your average watch - are to be found in the Altimeter and Barometer functions. The Core measures air pressure to determine both altitude above sea level, and barometric pressure. This Core is very good at this, but in order to get accurate readings, it is vital to regularly set a reference value. This is most easily achieved by setting the reference value to your current altitude, which you can determine from contour lines or other markings on your map. For example, I know that my home is 830ft above sea level, so I can quickly set a base reference and get accurate readings for whatever I do next.

Altitude references are easily set by pressing the View button in Alti or Baro mode.

The reason for needing a reference value is that air pressure changes both with altitude and with weather patterns, so the watch must somehow be able to determine whether the air pressure is changing because of your movement up or down, or because the barometric pressure is rising or falling.  The Core must therefore be told that air pressure is going to be changing because of altitude, or changing because of barometric pressure. Suunto have developed a clever automatic mode to cope with this, which is reasonably accurate most of the time.

Current altitude at home (in feet, because America hasn't yet joined the rest of the world)

In AUTO mode, if you remain at the same altitude for about 10 minutes, the watch switches to barometer mode. If it detects a sudden change in pressure it switches back to altimeter mode, and gives a little chirrup to let you know.

But often, while you're walking and experiencing altitudinal air pressure changes, the air pressure is also changing throughout the day as weather fronts pass through. Thus the sensor is apt to get confused and give slightly inaccurate readings.

To complicate matters further, let's say you're walking when when a low pressure approaches fast. The watch will then think that your altitude is rising instead of the air pressure falling.

For this reason, I eventually stopped using the automatic sensor, and now switch manually between ALTI and BARO modes. This is relatively simple - in fact Suunto are to be commended on making a fairly complicated watch easy to use with only 5 buttons. 

When I'm hiking, I switch it to ALTI mode. When I get into camp, I switch to BARO. That way, when I move it records the altitude, and when I stop - generally overnight - I get a record of the barometric trends. 

With its handy graph, I'm able to determine what the air pressure has been doing overnight, and whether or not it's likely to rain or snow.

The barometric graph shows the last 24 hours, and the reference altitude at which measurements are taken. Here, pressure has fallen gently, and recently started to rise. Outside today, the wind got up, but the skies are clear. I can assume that tonight it will stay dry, and probably get colder as higher pressure moves in.

The Core also features a Storm Alarm, which sounds whenever a sudden, rapid fall in air pressure is detected - and hence is also dependent on accurate reference values. I've found this to be quite useful. Last winter it accurately alerted me to several sudden snowstorms which blew in within 20 minutes of the alarm going off. However, it really only works efficiently when the altimeter and barometer are manually set. In automatic mode, the alarm might also be triggered by driving along a long flat road, and then up a steep hill. This is the inherent problem with the automatic sensor - it works well most of the time, but it's trying to measure two scales using one set of data.

I've found the altimeter function to be fairly accurate, but of limited use. While driving from Minneapolis to Denver and over the Rockies, it accurately tracked teh gradual rise to Denver's 5000ft altitude, and the sudden rise to over 10000ft as I crossed the continental divide. While in Utah, I used the log function to track a couple of hikes. This produces a result similar to the elevation graph of a GPS unit. Neat, but useful? I didn't think so, and haven't used it since.

The elevation log during a hike. A detailed, scrolling version is also viewable.

I was also pleasantly surprised after flying to Finland via three planes that on arrival the altitude was almost spot on at 50m in Järvenpää, and only 3m out at sea level in Helsinki.

I suppose if I were 

climbing the North Face of the Eiger

, or regularly in areas where altitude sickness might be an issue, it might prove useful. Generally I get by without needing to know the altitude, and most places just knowing that "I'm up a bit now" is more than enough.

So, to summarize the alti/baro features: the barometer is definitely useful to have, providing you are diligent in checking reference values. The storm alarm also could be useful. As for altitude measurement - it depends on your situation. It also, by the way, measures depth to 30m, and as a result the watch is completely waterproof.


The Core features a digital compass, with a bearing-tracking function. Depending on the model, some Cores have a rotating bezel which can be used to sighting a bearing. The Core Extreme forsakes this feature and replaces it with minimal curves and a red flash which for some reason remind me of a


sculpture. I've not missed the rotating bezel, as in practice the bearing tracking feature of the compass works without it anyway. You simply point at the thing or bearing you wish to head towards, press set, and the watch tells you to turn left or right.

I am heading at a bearing of 177 degrees, directly into the cupboard.

The compass draws a lot of battery power, and when using at night the backlight flashes on and off to conserve power. It's a bit weird, to be honest, but apparently necessary.

It's nice to have the compass, but have to say that I don't trust it. In Utah, while down in the canyons, it mysteriously malfunctioned. It would only register directions in a small quadrant from west to southeast. I couldn't get it to point north. I thought it was due to some magnetic rock (some have iron deposits in them) but in the end I think it was a fault.

Annoyingly, the software doesn't feature a 'recalibrate compass' option. The manual recommends rotating the watch to recalibrate, but that didn't work for me. I had to unscrew the back, remove the battery, refit it, re-assemble it, and try again. Then it worked.

As I was writing this, I've changed the battery (it lasted 1 year, almost to the day), and the compass stopped working. I just got a blank screen where I should have been led through the recalibration process. I've rotated the watch for ages with no luck, then opened it up, cleaned it again, and put it back together - then it worked. This kind of thing reiterates my doubts about the reliability of the compass. As a backup or last resort it's fine, but I'll stick to a more traditional compass when I really need to use one.


The Core has a thermometer, but you have to take the watch off and leave it for 10 minutes to get an accurate reading. Personally, with my absent-mindedness, I don't want to take off my expensive watch and leave it hanging around to find out if it's cold. I usually have a pretty good idea.


Yes, that's right, I'm talking to you. So put down the oven mitts and duster and pay attention.

I'm kidding of course, but are Suunto? I say this because there is a women's version of the Core - the Lumi. I bought one for Minna for her birthday last year so let's do a quick comparison.

The Lumi shares the same functions, but the software implementation is a little more limited. The most significant difference is that there is no altimeter or barometer logging graph. I don't understand why Suunto would choose to limit the Lumi in this way, but the manual for the watch gives some indication.

In the surprisingly well written manual for the Core, usage tips are given for exciting situations such as yachting, mountain climbing, and hiking.

But for the more feminine Lumi, we are treated to the following:

"The wristop is not just for outdoor-related activities. You can be original and use it indoors as well – perhaps to navigate through a crowded department store!"

Finland. A country which prides itself on gender equality.


Despite Suunto's grandiose claims that its products are wrist-top computers, the Suunto Core is, in fact, simply a watch with a few useful features for the outdoors.

But is it essential? Not really. The most useful function by far is the barometer. For the rest, I can live without most of them. I've used the sunset/sunrise feature on occasion, and the altimeter is fun, but more of a gimmick unless you're into serious climbing.

As you can see, my Core Extreme has an inverted, black screen. While this is undoubtedly cool and very James Bond, it is occasionally hard to read. The traditional LCD screens of some other Cores are considerable easier to read.

The Core is easy to use. It's software implementation is simple and easy to navigate. This is it's main advantage over Suunto's 'low end' watch - the Vector. The Vector is a plastic, more primitive version of the Core, but offers essentially the same feature set. If I were to buy another Suunto, and didn't want to pay the design surcharge, I'd probably go for the Vector. It's cheaper, more rugged, and perfectly adequate for backcountry use. The only thing in the Core's favour is that it is more user-friendly, and has some logging functionality (which I find I never use).

Do I like the watch? Yes - I wear it everyday, and will continue to do so. I may not use every feature, but whenever I go hiking I always use the barometer. It's good that it is waterproof, and the fact that it looks stylish enough to wear all the time is a bonus.

As I said, it's not essential gear, but if you fancy a watch for the outdoors,

you could do much worse


Buy one from


(and build up that dividend!), or