The Casio G-Shock Rangeman can harness the power of the sun to keep you going when you're in the wilderness, miles from a plug socket.
That's because it's the world's first solar-assistant GPS navigation smartwatch. It's also the first smart G-Shock watch, so the Rangeman is breaking a lot of new ground.
Its rugged looks, mud-proof design and GPS means it's targeted at those who spend most of their time outdoors - this isn't a stylish statement wearable you'd wear to a club.
Casio G-Shock Rangeman release date and price
The Casio G-Shock Rangeman release date is set for April, which means you have a few months to save up. And save up you will more than likely need to.
That's because the G-Shock Rangeman price comes in at $800 (around £600, AU$1,000), which makes it one of the most expensive smartwatches around.
The Casio G-Shock Rangeman is a beast of a smartwatch. It's big, brash and brutal, dominating your wrist.
While that might not make it practical as a daily timepiece, that's not the reason it exists. The G-Shock Rangeman has been developed to survive the rigors of the outdoors.
Not only is it water and dust resistant, it's also mud resistant. Gaskets have been fitted to the buttons to ensure the brown stuff doesn't sneak inside when the weather turns grim.
While this is handy, it does make the buttons a little difficult to press. You need to apply some force, and fully depress the five buttons for the action to register on screen. A light tap of a key won't give you any results.
You get three chunky buttons on the right of the case, with the central crown also rotating, allowing you to scroll through menus and options.
On the other side you'll find two more buttons, with the lower one programmed as the back key for the interface.
Casio G-Shock Rangeman hands on gallery
Solar power and GPS
You'll notice that there's a sizeable bezel running around the display on the G-Shock Rangeman, but as you may have already guessed there's a good reason that.
Yep, that's the solar panel, allowing the watch to harness the power of the sun and top up its battery.
Specifically the solar-assisted charging tops up the battery for the GPS. The on-board GPS can be used to plot routes and track your progress live on-screen.
GPS is usually rather power hungry, which means battery life can take a real hit if you're using it continuously.
A full standard charge of the G-Shock Rangeman can give you up to 33 hours of continuous GPS use, but the solar panel can up that to 48 hours, allowing you to track your location for two full days in the wild without the need to find an alternative power source.
Four hours of sun will produce around one hour of GPS usage, so it's not the fastest, but it could well make all the difference if you are somewhere remote.
Display and interface
Unlike most smartwatches, the Casio G-Shock Rangeman has a rather basic black and white display.
It makes sense, as it's easier to see in bright light and is less power hungry, giving you better battery life.
Thanks to the sizable bezel of the solar panel though, the screen is also quite small with menu text being rather small. If your eyesight isn't great you may well have trouble reading what's on screen.
It's also not the most intuitive watch to use, with various menus and sub menus, and abbreviations of features which don't make it clear to more novice users what's going on.
Once you've got the hang of scrolling lists and selecting options using the crown button, and returning to the previous screen with the back button it does get a little easier to use, but there could be quite a steep learning curve initially.
It links to your smartphone via Bluetooth and the dedicated application will be available on both iOS (iOS 10+) and Android (Android 6+).
The app provides more detailed information and data about your terrain, routes and movements which the watch screen can't display.
The Casio G-Shock Rangeman is an expensive, brutish smartwatch which doesn't have a great screen or showstopping looks - but in reality, non of that matters.
It's a smartwatch with a very specific purpose and for a certain audience it could well be a very powerful tool.
The introduction of the solar-assisted charging could be a big step for wearables though, and it could lead to more devices taking advantage of the sun.
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