Back in 2019, when Casio launched the G-Shock GA-2100, no one could have predicted quite how popular it would become. Now one of the brand’s most recognizable models, it didn’t take long for the watch to become the coolest G-Shock available. It earned the nickname “CasiOak” due to its eight-sided bezel, loosely resembling that of the AP Royal Oak. The CasiOak also became a perfect canvas for bespoke and colorful customizations from the capable hands of the IFL Watches Team. Today I’m looking at the brand’s latest creation, the G-Shock CasiOak Deep Sea Diver.

Until now, most of those customized pieces have seen a colorful blast of abstract patterned dials or enhancement concentrated solely on the large and prominent indices of the stock model. The CasiOak Deep Sea Diver is the first creation from IFL Watches, which departs from the abstract and moves firmly towards a detailed and naturalistic image. Each hand-painted dial shows an underwater seascape complete with its own little diver immersed in the tranquillity of the ocean.

Getting lost in the ocean’s depths

This watch is all about the dial. Well, that’s not strictly true. But upon seeing it for the first time and for the purpose of this review, that’s what I’m concentrating on. Only 100 pieces of the Deep Sea Diver will be available. Each one is hand-painted, and each will be unique. The shifting color palette, from bright turquoise at the top of the dial down to a murky blue at the bottom, is a nice tidy analogy to the change in light and colors beneath the surface of the seas. The gradient effect also successfully camouflages the borders of the LCD display to some extent, though the information in the panel itself is no more or less easy to read than on a stock model.

The base layer of color is more than just a backdrop, though. The paint has a shimmering pearlized effect, most noticeable on the chapter ring. The dial is then flecked with white and turquoise to give the impression of marine life in the depths and sea foam above. As another departure from the original GM-2100CB-1A reference, the large indices and bezel markings are painted white to represent the crest of breaking waves. Despite most modifications concentrating on the artistic and poetic, the decision to highlight the bezel markings swims against the tide and gives this true tool watch more usability.

I can’t help thinking back to my short-lived stint with a Vostok “Scuba Dude” when I see the diver painted on the dial. Though here, both the theme and execution are on a different level. It’s tough to imagine the skill, precision, and patience required to hand-paint a marine scene on each dial. Still, it’s easy to appreciate the result.

Beauty and practicality

Under the surface, the CasiOak Deep Sea Diver is a run-of-the-mill G-Shock. That means there’s no Bluetooth, GPS, or Altimeter/Barometer/Compass. But you still get world-time functionality, alarm, stopwatch, and countdown timers in the rugged and lightweight shell that has made G-Shock famous. Much of the watch’s charm is the contrast between a capable tool watch and a dramatic and artistic dial. But that pleasing contradiction comes at a price. A beautiful dial sitting inside a cool but (let’s face it) less graceful case causes no issues. It’s a nice separation of the two themes. I find it challenging to look at the dial without getting drawn in, closer and closer. And in doing so, some flaws that you would expect and accept in a €200 G-Shock become more pronounced.

With those first few hours getting lost in the dial out of the way, I’ve also thoroughly enjoyed wearing and using the CasiOak Deep Sea Diver. While I haven’t taken it to its spiritual home beneath the waves, I’m always surprised how much I use any particular function when it suddenly becomes available on my wrist. Timing my children as they each race a lap at the local park – check. Setting a timer to go and inspect dinner cooking on the hob – check. Cycling through world time zones to remind myself what the local time is for some of my colleagues overseas – check. Nothing about the customization of the watch hinders those useful functions in any way. None of that has come as a surprise.

The CasiOak Deep Sea Diver on the wrist

What has surprised me is how comfortable the watch is. Despite being a larger G-Shock model at 44.4mm in diameter and much longer than wide, it doesn’t feel overbearing. Not only is the watch lightweight, but the fabric strap with two stainless steel keepers gives a comfortable experience in a way that resin bands don’t always provide. The lug adapters connecting to the watch’s main body allow for any 21mm band. The adaptors push the overall length to almost 60mm. But that additional length is already contoured around the wrist. Therefore it looks more like it is part of the strap than part of the watch. I never felt that the watch looked or felt too large on my 17.5cm (7″) wrist. Alternatively, you can remove the adapters and fit a standard G-Shock resin strap.

Is the Deep Sea Diver the start of a new direction?

The sheer intricacy and the amount of human skill and effort on show elevate the CasiOak Deep Sea Diver well above its original form with a fresh, creative twist. I think an analog G-Shock display makes for a clever canvas for a delightfully intricate hand-painted dial. It allows for a connection between a painted scene and the function of the watch in a way that would be severely restricted in a dress watch, for example. With this particular customization also being quite a departure from IFL’s previous offerings, it will be interesting to see if this is a direction that the brand explores further. For more information about the CasiOak Deep Sea Diver, you can visit the official IFL Watches website here.

Watch specifications

IFL Watches CasiOak Deep Sea Diver
Hand painted
Case Material
Resin / Stainless steel with a black ion-plated bezel
Case Dimensions
44.4mm (diameter) x 49.3mm (length) x 11.8mm (thickness)
Case Back
Stainless steel, screw down
Casio module 5611
Water Resistance
Fabric band
Analog time display (hours and minutes) with separate digital display. World time, stopwatch, countdown timer, LED light, alarm, calendar
Special Note(s)
Hand-painted, limited to 100 pieces