Rugged but huge

The photos don't fully convey how big this watch is. It's massive - big, thick, and heavy. If you buy it online without having seen it in person, you may be surprised as I was. It's not unwearable, but it will certainly look pretty big on your wrist, and it may take you some time to get used to the size and weight. I am getting more accustomed to it over time as I wear it though.

Why so big? Well, I assume it's due to the bulk of the shock protection, the atomic time signal receiving equipment and the solar cell/rechargeable battery, three of the key features. Casio's "G-Shock" line is designed to be rugged, with "shock absorbing structure", as the name suggests. The watch itself is mostly metal, with a few plastic bits. This model has a segmented metal band with a snap-closed clasp. The face of the watch is slightly recessed to avoid scratching. I can't verify the internal shock protection, but it seems like a sturdy design. (Not that I've had a lot of problem with any of my other watches breaking from shock.) It's rated for 20 bar pressure (or 200 meters depth) water resistance, which is the standard for scuba diving.

Adjusting the size of the band to your wrist by removing links with a pin or fine screwdriver is the usual painstaking process, but probably you'll only have to do it once.

There's a nice big HH:MM:ss time display in the middle of the face, which I think is always an important feature. Month and day below, 3-letter day of the week spelled out above. This basic information is quite clear, so no complaints there. On the other hand, the layout of the battery indicator at the upper left of the face is a bit weird, and the indicators which appear on the display for other settings (including the important AM/PM) are tiny and randomly placed. There are 2 other nearly-identical models of this watch which differ only in the layout of the above items. I'm not sure why, but apparently Casio tried 3 times to get it right, and didn't quite achieve a harmonious design with any of them!

There's an EL backlight activated by a button below the face which provides plenty of light to see the time in the dark. There's an optional setting to have the backlight activate automatically when you flick your wrist away and then back with the watch face toward you (as long as it's dark - the watch senses ambient light via the solar cell), but considering that it's easy to find the button and the auto-illumination can activate accidentally, I leave it off.

The 4 control buttons on this watch are all recessed in the corners, making them a little difficult to press. I prefer to have a couple of buttons on the face which are easier to press for stopwatch functions and such, but as recessed buttons go, these ones aren't the worst I've encountered. As usual it can be a bit of a challenge to remember how the 4 buttons are used for various settings and control functions without consulting the manual, but it's no worse than other watches.

The automatic time setting feature of this watch is neat. It receives a broadcast signal from the Bureau of Standards atomic timekeeping station in Colorado and sets the time automatically, either when you press the Receive button, or automatically once a day in the early hours of the morning. The signal is supposed to be receivable for up to 2000 miles from the broadcast station, but obviously it depends a lot on reception conditions. I'm at less than half that distance, and the signal strength is quite variable around my house. However, the automatic setting does work when I leave the watch on my dresser at night, just as intended. It has also worked fine in a few other cities that I've travelled to around the country, even from within hotel rooms in concrete buildings. It takes a couple of minutes of stable signal to receive the time, as the broadcast station's cycle takes a full minute to send the complete time and date information at its very low data rate. A small display at the lower right of the face shows the status of the last reception, allowing you to confirm that the time is synchronized, or the actual signal strength while the watch is actively receiving. The time received is supposed to be accurate to within a second, and it seems to be since it matches GPS satellite time exactly on my car nav system. It's nice to know that time shown by your watch is exactly accurate, and to be able to confirm at a glance that is has been synchronized in the last 24 hours.

This watch uses a solar cell to power a rechargeable battery. I hope the advantage will be that I can use the backlight and alarm whenever I want and the backlight won't fade to invisibility the way it does so quickly on other watches with regular long-life batteries. However I'm still not sure that the rechargeable battery is a great idea. I know that in general rechargeable batteries don't last all that long before they lose their capacity, and it will be more expensive to replace than a regular battery. I've also read some complaints from owners of this and similar Casio watches that the rechargeable battery had a short life, and that the remaining-capacity indicator tends to drop very suddenly from full to nothing when the power starts to run out. I guess we'll see. Casio claims the watch will run for up to 6 months of normal use on a full battery charge when new (it automatically shuts down the display when left in the dark to save power). According to the manual it doesn't need a lot of light to maintain the battery charge in normal use, but it does take a few hours of sunlight to restore it fully if you run it down completely, e.g., by using the backlight a lot.

The other functions are all fairly typical for a Casio digital watch. The Mode button cycles through the various modes, and the other 3 buttons are used for adjusting the settings in the other modes. It's easy to set your time zone to work properly with the automatic time setting, and there's a World Time display mode which is equally easy to use. There are 4 daily alarms and a "snooze" alarm. The alarm isn't very loud, but it's adequate. There's a standard stopwatch function with lap times, but oddly there's no countdown timer. This watch has a Time Memo feature, which lets you record up to 30 times in memory by just pressing the Time Memo button (this is listed as "30 page memo function" in many places, causing confusion with the alphanumeric memo feature found in other Casio watches - just to be clear, this watch does not have any alphanumeric memo feature).

Overall, not a bad sports watch - if only it weren't so darn big!