A lot has been shown about this watch on the internet: all of the specs and features are usually explained well, but few reviewers have actually tried to use the watch in real outdoor situations where a watch like this can save your life.
We did, and found some strengths and weaknesses.
First off all you better make sure that the watch is fully charged before going on a hike. The battery needs to be at a minimum level of 80% (!) for navigation to work. Once below 80%, navigation just stops. Maybe Casio decided to reserve most of the battery for keeping time? We would prefer that all of the battery was kept for GPS and compass. What good is knowing the time, if you are lost in the middle of the woods without navigation functionality? There must be some technical reason for this.
Fortunately, the battery lasts a very long time, even when using GPS. Switching to normal mode will keep it going all day long without problem. Make sure to bring a charger if you are going on a trip that spans multiple days. The solar cells might not be sufficient to keep navigation going for multiple days in a row.
Update on the battery life: today we did an extra test. Sunny winter day here. In the early morning, we started off with a trip that used about 2 hours of continuous navigation. We did not charge the watch prior to our trip. It still showed full bars when we left. After that, we used it as a normal watch inside the office for about 8 hours. Then we did another trip using the navigation for about one and a half hour. GPS was set at high rate. We did not point the watch to the sun, it was mostly in the shadow. Even now, about 4 hours after the evening trip, the watch still shows full bars. Truly Amazing!
Tip: Always store your starting point in point memory before you start going. If you quit navigation for some reason, you can no longer backtrack. The only thing the recall activity function allows you to do, is to change the name of the activity or delete it. There is no way to load a previous activity for navigation purposes using only the watch. So if you are hiking for multiple days, and stop navigation while sleeping for example, there is no way to backtrack from the watch. You can, however, load the logs onto your phone, and create a new route based on your activity, and send it back to the watch. But if you saved your starting point, you can simply navigate back to that from the watch, without the need for a smartphone.
By storing your starting point, or creating a route in advance, you can save a lot of battery also. No need to keep navigation going all of the time. Just start it up now and then to check if you are still going good, and then quit it again. This is how we use our other outdoor watches also.
GPS is very accurate. We estimate a maximum deviation of about 15 meters, but most of the times it is much better. Enough for most purposes that this watch is intended for. But reception is a bit weak. It can take multiple tries to get a fix, and most of the time it will take at least a full minute to acquire a fix, and often it will even take several minutes. Once you have a fix, it stays connected without problem, but stay away from high buildings. This watch is not suitable for city environments.
We set out on a trip, without creating a route. We just started walking without paying attention, and then we tried to find our way back using just the backtrack function of the watch.
First thing we noticed is that the map display is useless for navigation purposes. Even the finest scale (2km) is far to coarse for that. The smallest detail you will see on that level is still 1km in size. You would need to walk at least a kilometer to know for sure that you are going in the right direction! On the picture below you can see that: we walked about 1km, making many turns of several hundred meters to the left and the right, but none of that is visible. And there is no way to zoom in further. There should be a scaling option for 100 meter to be able to use the map for navigation. Garmin Fenix watches have no problem with that.
However, you can use another scaling option that shows you the direction you need to go and the distance. You just need to pay attention that on top of the display it shows you your goal, otherwise it will point you the wrong way. You can change this with the A-button of the watch. If things make no sense: just press the button untill it shows “G” (for “Goal”) on top, and you are good to go.
Many reviewers claim that the backtracking function sends you back on the same path that you came. This is not the case. It points you in a straight line to your starting point. This is a good thing, because often you want the shortest way back. Just hold the watch in front of you, as horizontal as possible, and as far away from your body as possible, and it will point to your starting point with very high accuracy. In our test, the watch brought us back to within 10 meters of our starting point. Very nice result indeed. Notice that there are no indications or instructions on the watch to turn left or right. It just shows you the direction to your goal and the distance. Out in nature, that is all you need. There are no streets and intersections. It is just like using a map and compass. We like it a lot. No real need for a map on your wrist.
When using the watch in cold weather, it became quickly clear to us that you will need to wear the watch on top of your gloves or sleeve. Not only for the GPS reception, but most of all because the ceramic back of the watch becomes very cold and feels like an ice-cube strapped to your wrist. So make sure the watch strap is big enough for you to make that possible, or hang the watch somewhere else on your vest in cold conditions.
Operating the watch in the dark without an external light source is nearly impossible. It has a led light, but the timeout can only be set to 1,5 or 3 seconds. Normally this is not a problem, but it also switches off while operating the watch. If you want to change a setting, or navigation option, in total darknesss, you will need to keep pressing the light button every 1,5 or 3 seconds to see what you are doing. The light should simply stay on as long as you are still operating the watch, but that is not the case. Best to bring a flashlight when going out in the dark for longer trips.
Our conclusion is that this watch does what is needs to do: it will bring you back when you get lost, or guide you quite nice along a route. As long as you pay attention to some basic things like starting with a fully charged watch, and saving your starting point, or store your route before starting your trip. Going unprepared on a hike is never a good idea, so this should be no problem at all.
Our tests have shown that compass, barometer and altimeter are very accurate indeed. Much better than any other Casio watch we tried, and on par with our top performer: the Tissot T-Touch.
Functionality and usability lack behind a watch like a Garmin Fenix however, while it costs the same or even more. Switching between information displays, like barometer and altimeter, take a lot of button presses and turns of the crown on the Casio. On a Garmin or Samsung watch, you can just scroll trough the different information displays. On top of that the crown also does not work very well. There is a lot of lag, causing you to over-scroll often. Many times it scrolls to a different option in the menu when you press the crown to select something, causing you to select the wrong option.
Sunrise, sunset and moon phase indications are accurate too. Tide levels could use a lot of improvements. The display always starts at 6 in the morning, instead of showing you the tide at the current time. You need to scroll all the way to the current time for that, using the crown. To find out the time of the next high or low tide, you also need to scroll to that. Other watches do a much better job here, showing you the current tide immediately, and displaying the times of the next low and high tides at the same time. The tide graph is far to coarse also, and the exact time for low or high tide can be difficult to judge. Sometimes you can be off by up to an hour because of that. No big issue, because this watch is not ment for fishing or navigating with a boat, but it woul be nice if Casio would improve this with an update.
Because of the usability issues, you might think we do not recommend this watch. In fact: we do recommend it, if you are going to use it for what it was intended. That is: bring you back home in extreme conditions.
For most people a Garmin Fenix will be a far better option for going outdoors. The new generation offers topographical maps, color display, and way more options and functionality and far better usability. It is also a top of the range sportswatch. And even the older versions that have no maps, and navigate in the same way as this Casio, are often better choices. The Casio is a bit tougher and can handle more extreme conditions, but the difference will not be enough for most people. The Casio will get you back when you are far away from any power source, or when temperatures drop below minus 20°C for example. You can use the solar charging to get going again, when the battery runs out. But remember that can take many hours, even in bright sunlight. The Casio is truly ment for extreme conditions, where almost no other watch or smartphone will help you. But in normal conditions, most other outdoor and sportwatches with navigation will be a better choice for many people. On normal days, however, when you are not using navigation all day long, you will never need to charge the Casio, and that could be a deciding factor for some people. We never needed to charge it since the first day we got it, and we regularly do small hikes for one or two hours per day with it. We like the Casio a lot, and it will always be part of our equipment when going on a hike, even if we take the Garmin also. That is how much we like it!