Shock- and water-resistant to 200 meters, the durable G-Shock Atomic Solar is suitable for wearing while mountain biking, chilling at the beach, or trudging to a campsite. Hikers with full packs, competitive runners, and swimmers will balk at the relatively heavy 2.4-ounce watch, encased in a not-especially-breathable black plastic resin. The four recessed function buttons are also difficult to press, which is less than ideal for stopping the timers with precision, especially if you're on the move.
Navigating the various modes and their functions will require some time spent studying the manual, and even then, it will take a while to get used to the interface. Of particular complexity is setting the time with the radio signal broadcast from the National Institute of Standards and Technology's atomic clock in Fort Collins, Colorado. Signal strength depends on your proximity to the source, so while anyone living in the United States is technically within range, those living within 600 miles of Fort Collins have the best chance of holding on to the signal. We tried calibrating from our office in New York, but our famed concrete-and-steel canyons lived up to their reputation as a no-man's-land for radio waves. And although the G-Shock takes a few minutes to tell you that it can't receive the signal, it reverts back to its currently programmed time, so you don't lose anything for trying.
As with all radio signals, distance, weather, and physical obstructions such as mountains and buildings interfere with the broadcast, so denizens of coastal cities especially may have to suffer the indignity of setting the time manually. At least you won't have to worry about reception for the solar charger, which can draw power from the sun as well as man-made light. There's even a handy power meter. The G-Shock is backed up by a one-year warranty, which feels skimpy given the brand's reputation for toughness.
Compared to other rugged, sporty models we've reviewed, the Casio G-Shock Atomic Solar watch is a little soft on features. Still, extreme-sports aficionados will like its durability, and environmentally conscious outdoorsy folks will surely dig that it's solar-powered. If you're looking for a lighter watch to take on your next hike, check out the HighGear Axis. Serious athletes and runners will find other products, such as the Nike Triax Elite and the Suunto X6-HR, better suited to their needs.