I bought this Casio GWM530A-1 to replace an old Timex Ironman. This review is based on my first few days of use. GENERAL: this model uses the Casio 3405 module, which it shares with other G-Shock models. English instructions came with my watch, others have said they needed to download the English instructions, which you can find here: [...] Key features are solar charging, atomic clock sync, G-Shock build, and 200M/20Bar water resistance (good enough for professional marine activity, surface water sports; not good enough to dive with). This is NOT ISO 6425 certified as a "dive" watch. Some reviews suggest this is not as waterproof as the marketing suggests. To be safe, consider not pressing buttons underwater. BUILD: solid - built like a tank. It has more heft than the Ironman. My Ironman had a 38mm diameter case, the GWM530A is about 46mm. As G-Shock watches go, this is actually on the smaller side (I looked at another model that had multiband WaveCeptor / Tough Solar and it was a whopping 53mm). This watch is about a centimeter thick - don't expect to slide this under fitted dress-shirt cuffs. This is the largest watch I own, and probably the largest I can pull off without looking ridiculous. For comparison, my daily dress watch is a 42mm automatic on a NATO strap. The case is chunky, dense. I like the aesthetic and the three mini-indicator circles. Not quite as retro as some of the other G-Shock watches. The indicators are, from left to right, a seconds counter, a solar charge indicator, and a multi-purpose indicator with six segments: 1) SIG - tells you if the hourly time signal is on or off 2) ALM - tells you if any of the 4 one-time alarms is currently on 3) SNZ - tells you if the 5th "snooze" alarm is on (an alarm that can be suppressed for 5 minutes at a time) 4) AutoEL - feature to automatically illuminate the face when you tilt the watch face to 40 degrees from level to view it in the dark 5) MUTE - tells you if button press "mute" is on - when off, there's a chirp when you switch modes (bottom left button). 6) DST - tells you if daylight savings time is on / off The strap is dense, premolded (the watch won't lie flat on a table) and appears to have strong mounts/screws to the lugs. Two slightly-recessed buttons per side that sit just below the edge of the case. I really like that they're recessed by about 1mm - it avoids accidental button-presses, which was a problem I had with my Timex whenever I extended my wrist. FEATURES: ToughSolar - the watch arrived partially charged. Needs a day in bright sunlight to get to "high", but once there will typically keep the charge. It will charge in cloudy light / incandescent / fluorescent bulb light, but more slowly. Charge can be assessed at a glance by looking at the middle circular indicator, which is divided into 3 zones (high, med, low). The watch has a power saving mode that you can turn on/off. In PS mode, the display will turn off when it's dark and the radio for atomic clock syncing will also turn off. I keep PS turned on, but it's never kicked in since my charge has never fallen below "medium". WaveCeptor - Casio's name for atomic clock time syncing. There are 6 atomic clock signals across the world that this will sync with. These clocks are accurate to within 1 second every million years. So, you know, probably good enough for whatever you're doing. The one for US / North America is in Fort Collins, Colorado. There's one in China, two in Japan, one in Germany, one in the UK. As long as you're within 1500km (about 900 miles) from the European or Asian clocks, or within 3000km (about 1900 miles) from the US clock, it should sync. I am in the mid-atlantic / Delaware Valley on the east cost of the US, and it will sync fine when I put the watch by the window overnight. The watch shows the strength of the signal (L1 = weak, L2 = med, L3 = strong). I get L3 if I position it just right. You can either set the time manually or have it automatically fetch from the atomic clock. You can also manually fetch the atomic time (like, when you first get the watch). It will automatically poll the atomic clock up to 5 times at night, until its successful. The scheduled times for N. America are between 12am and 5am. Lots of reviews indicate people have issues with syncing, but Casio is very clear about why syncing works better in some circumstances than others. All I can recommend is that, if you're having trouble, you systematically go through the steps in the manual. EL and AutoEL - the "G" button at the bottom of the face turns on the electroluminescent backlight for either 1 or 3 seconds (you choose the duration). In addition, there's an autoEL mode where, when it's dark, the gesture of moving the watch face from level to tilted by 40 degrees (basically, the gesture of tilting your wrist to see the face) will turn on the backlight. This is a very intuitive and useful feature! Timekeeping Mode - it's a watch with AM/PM, h/m/s, month, date, and day indicator. Because of the atomic clock function, it automatically deals with leap year as well as daylight savings time (which you can also manually override). First step when you get the watch is to specify your home time zone. Also recall that the time syncs to atomic clocks between midnight and 5am. That means if the set time is way off when you get the watch, it won't sync (it will poll the atomic clock at the wrong times of day, when signal is weakest). That means you may have to manually set the time when you first get the watch, just to get it to poll the atomic clock correctly. Pressing the bottom right button toggles between either showing the date/day or a secondary time zone (world time) at the bottom of the display. Left circular indicator is a seconds indicator with 10 segments. The circle counts up 10 seconds then counts down 10 seconds. So it's a relatively easy way to visually divide a minute in multiples of 10 or 20 seconds. That being said, I don't use this indicator much. World Time Mode - great feature. With one button press, you can switch to world time mode. The right 2 buttons move you from timezone to timezone. Up is westward, down is eastward. You can also manually set/override daylight savings time in world time mode. Alarm Mode - individually set up to 5 alarms per day: four one-time alarms, and one "snooze" alarm. The alarm isn't super loud - don't count on this to wake you from a deep sleep. Stopwatch mode - standard stopwatch with start, stop, split, restart, and clear. Timer / Countdown - set a countdown timer in hours/ minutes up to 24hrs. You can't set a timer for less than a minute, in case that's an important feature you need. SUMMARY: This is my first G-Shock. I got this for less than $90, about twice what I paid for my Timex Ironman. But it's an amazing value - you never have to change the battery (eventually, you might have to replace the rechargeable battery), you never have to set the time/date/DST, you don't even have to press a button to view the time in the dark. Very high quality build and feels more solid/hefty than the Ironman. I think it's at the sweet spot for size at 46mm diameter - totally useable as a daily beater, not too flashy, looks dressy enough for work. If you're looking for a full-featured, shockproof, waterproof watch with solar charging / atomic syncing, consider this one.
