The nickname arrived before the watch did. Nine references from Casio's unannounced G-Shock GMC-2500 and GAC-2500 series appeared briefly on Casio Japan's own site, apparently by accident, before the page turned into a 404. Enthusiasts took one look at the broad shoulders on either side of the cushion case and called it the CasioNaut.

It's a decent joke, and it follows the CasiOak naming convention that stuck to the GA-2100. But the Patek comparison is also the least interesting thing about this watch, because buried in the leaked spec sheet is a genuinely novel piece of engineering.

The Magnetic Hands

G-Shock's founding problem has always been the same: how do you keep a watch working after you throw it at a wall. For forty years the answer has been layered shock absorption around the module. The 2500 series takes a different approach for the hands themselves.

Rather than fixing the hands rigidly to a shaft, Casio's Magnetic Holding Structure holds them in place magnetically. Under a hard impact the hands can shift or deflect rather than snap, then return to position. It's a solution that accepts temporary misalignment in exchange for not breaking, which is a real trade-off rather than a marketing line.

Casio appears to know the trade-off is real, because the leaked module includes a "Hand and Day Indicator Alignment" function specifically for manually correcting hands and the date indicator after magnetism or impact knocks them out of position. That's an unusual thing to build into a watch, and it tells you Casio expects this to happen occasionally.

Why Analogue Matters Here

This is the part most coverage is skipping. The GA-2100 that spawned the CasiOak is analogue-digital, with a small LCD panel on the dial. The 2500 series is fully analogue.

That means Casio can't fall back on a digital display to carry the functions, which is why the two-eye layout exists: small seconds at 9 o'clock, a three-cell date window at 3 o'clock that doubles as a mode indicator. There's a Shock Resist marking on the tail of the seconds hand, a hand shift function to move the hands clear of the indicators, and a 1.5-second LED dial light on the upper right button.

Casio's now-deleted page traced the design back to the DW-5000C, the original 1983 G-Shock. That's a stretch visually, but the reasoning holds: this is a shock-resistant watch built around a fully mechanical display, which is closer to the original brief than adding another screen would be.

The Leaked Lineup

Three case constructions across nine references:

• GAC-2500 - resin case and strap, 46.7 x 44.5 x 12.7mm, 47g, in black, green, white, and yellow

• GMC-2500 - stainless steel bezel with resin strap, 46.7 x 43.8 x 12.9mm, 68g

• GMC-2500D - stainless steel bezel and bracelet, 46.7 x 43.8 x 12.9mm, 138g

All carry 200 metres of water resistance and roughly two years of battery life, with a seconds-sleep function to conserve power. The weight spread is worth noting: the resin GAC at 47 grams is nearly a third of the full steel GMC-2500D at 138 grams, which will matter more to daily wearers than the bezel material does.

Pricing, With a Caveat

Japanese pricing from the leak puts the resin GAC-2500 at ¥20,900, the steel-bezel GMC-2500 at ¥37,400, and the full steel GMC-2500D at ¥49,500. In US terms that's roughly $134, $240, and $320, though currency conversion isn't how Casio sets international pricing and the actual US figures will likely land higher.

Release is expected in November 2026, in Japan first. No confirmed international dates.

Worth stating plainly: none of this is official. Casio hasn't announced these watches, the product page was pulled, and everything above comes from a brief listing error plus enthusiast reporting. Specs and prices could move before launch.

Whether It'll Land

The CasiOak worked because it delivered a recognisable luxury silhouette at a G-Shock price, and it did it at a moment when integrated-bracelet sports watches were the hardest things in watchmaking to buy. The CasioNaut is chasing the same trick with a different template.

The difference is that the GA-2100 had a genuinely clean, minimal dial that happened to look expensive. This one has more going on, and whether a two-eye analogue layout with a mode-indicator date window reads as elegant or busy is going to come down to how it looks in the metal.

The magnetic hand structure is the part that should outlast the nickname. If it works as described, it's the kind of quiet engineering solution that ends up in G-Shocks for the next decade, long after everyone stops making Patek jokes.

For anyone who wants the G-Shock toughness without waiting on a leak to become a product, Watch Gang's Casio and G-Shock lineup covers the current catalogue, and the broader digital and hybrid selection is worth a look if the analogue-digital format is what you're actually after.