When the GA-2100 launched in 2019, its octagonal bezel and integrated band immediately drew comparisons to the Audemars Piguet Royal Oak — a watch that costs roughly 300 times as much. Enthusiast Steven Davila, posting in the Scottish Watches community, coined the nickname "CasiOak," and it spread fast enough that Casio's own design team eventually leaned into the comparison rather than fighting it, even while maintaining the octagon actually traces back to the brand's own original 1983 DW-5000C.
The GA-2100RL-1AJF carries that silhouette forward with a sportier finish — a red, blue, and yellow accented bezel with a brick-pattern texture — while keeping the core spec sheet that made the original a sleeper hit: 20 ATM water resistance, world time across 48 cities, and Casio's standard shock-resistant construction, all in a case thinner and lighter than most G-Shocks that came before it.
