It’s not every day that you get to handle an icon. Still rarer are the times when, through some whim of the universe, you’re offered the chance to evaluate an upgraded version of a classic.

But when Casio came calling, that’s exactly what they were offering. The brand’s latest G-Shock, the GA-B2100 ($150), is a model with a storied lineage. So much so that it has its own nickname — the “CasiOak.” This comes from its silhouette, which bears a passing resemblance to the much more expensive, far less practical Audemars Piguet Royal Oak of hyper-luxury fame.

True, the new GA-B2100 may not have a tourbillon or minute repeater. But with the addition of Bluetooth connectivity and solar charging, it’s as if Casio squirted hot sauce all over an already delicious, octagonal pizza.

These particular condiments resulted in a $60 price hike from the previous gen and, after a few weeks of testing, I can confirm that they’re worth the extra charge. Read on to see why the B2100 CasiOak is one of the best adventure watches in the competitive outdoor space.

In Short: The G-Shock GA-B2100 is a good thing made (almost) perfect. By adding Bluetooth time-syncing and solar charging to one of their most popular designs, Casio has elevated the CasiOak into something of a modern classic.

Its intuitive layout, feature set, and rugged durability make it one of the most compelling timepieces under $200.
We’ll get to the features in a minute, but first, we need to talk about size. My biggest complaint with G-Shocks has always been this — most of them are too damn big. It’s why I’ve gravitated to their digital offerings, such as the classic GWM5610-1. But the GA-B2100 manages to avoid this issue, with a sensible diameter of 48.5 mm.

Best of all, the watch rises only 11.9 mm from the wrist. All this amounts to an incredibly wearable piece, buoyed by a weight of just 52 g.

Once it’s on your wrist, the CasiOak is an incredibly unfussy watch. While many G-Shocks suffer from legibility and operational learning curves, the B2100 is as intuitive as can be.

The face is open, the indices are well-defined, and the small LCD window is perfectly positioned. The upper left button switches day/date display, and the lower left cycles through its world timer, stopwatch, alarm, and countdown timer functions. Casio’s Super Illuminator is triggered by the upper right, casting a bright light over the dial. The last, lower-right button is reserved for various settings and operational functions, all of which can be found in the included manual.

And see that little sub-dial near 9 o’clock? Beyond its use as a mode indicator, it’s also a gauge for the internal capacitor. After a few hours in the sun, the Tough Solar function should have the arrow pointing at H (high). As with most G-Shocks, the GA-B2100 features an exemplary 200 m of water resistance. But unlike its predecessor, this model can be synced with your phone through the Casio Watches app. This operates sort of like the WaveCeptor function found on the GWM5610-1.

Except, instead of listening for the atomic radio signal, this new CasiOak checks its internal time against the clock in your cellphone and adjusts itself accordingly.

A quick note about the band — personally, I like the resin. It’s lightweight, comfortable, and fits the watch’s go-anywhere ethos. However, if you really want to swap it out, conversion kits are available. G-Shocks are meant for adventure, and the B2100 is no exception. This loaner accompanied me in the kitchen, on an overnight test run of my backpacking setup, and through several working days under rather challenging conditions. I wish the stories were as colorful as the photos, but honestly? The CasiOak just works.

How about a brief list of the things it withstood? Let’s see — sinks full of suds, large quantities of sunscreen, bug spray, sweat, sessions at the gym, photos in the sand, and probably a couple of dozen bike rides and showers between.