CasioNaut: the new G-Shock GAC-2500 e GMC-2500 watches

Enthusiasts are using CasioNaut as a nickname for the new G-Shock GAC-2500 and GMC-2500, two analogue models with soft-touch, rounded cases.

Their silhouette immediately drew comparisons to the Patek Philippe Nautilus, although CasioNaut isn’t an official name.

Beyond the visual similarity, Casio describes the new models as analogue reinterpretations of the 1983 DW–5000C, the original G-Shock.

Shock resistance remains the starting point, while flowing shapes and an uncluttered dial take the design in a new direction.

CasioNaut: why the new G-Shocks recall the Nautilus

The comparison stems largely from the case shape, with its pronounced flanks and rounded surfaces.

Compared with the sharper geometry of many G-Shocks, the GAC–2500 and GMC–2500 look closer to integrated sports watches.

The Nautilus reference is the watch community’s interpretation of the design. Still, the brand draws on its own heritage, specifically the DW-5000C.

A similar nickname exists within the G-Shock lineup. Enthusiasts nicknamed the GA-2100 the “CasiOak” because its octagonal case resembles the Audemars Piguet Royal Oak.

That unofficial name quickly became part of collectors’ vocabulary. CasioNaut is the second in a row, this time referencing the Nautilus.

From the DW-5000C to an analogue G-Shock

Launched in 1983, the DW–5000C was built around one defining principle: shock resistance. The new models reinterpret its design, replacing the familiar digital display with an analogue layout.

The case’s curved surfaces create shifting light and shade as the viewing angle changes. By contrast, the dial is deliberately restrained, with crisply defined hour markers designed for legibility.

This marks a meaningful shift for G-Shock: the brand’s identity remains unmistakable, but its proportions and styling are less closely tied to the classic digital watch.

Multi-Mission Date: one window, multiple functions

The main technical feature is the Multi-Mission Date display, which adopts a three-cell window at 3 o’clock.

Depending on the selected function, it shows the date, elapsed stopwatch minutes or other setting-related information.

Setting the year, month and day enables a fully automatic calendar, eliminating the need for manual date corrections.

You can stop the subdial hand at 9 o’clock when you don’t need it. Casio says this reduces power consumption and extends battery life.

GAC-2500 and GMC-2500: the available options

Nine are the new references; the GMC–2500 models incorporate metal components, while the GAC–2500 models use full-resin construction.

The GMC-2500 range includes:

• GMC-2500D-1A: black dial and silver-toned finishes;
• GMC-2500D-1A2: blue dial;
• GMC-2500-1A: black dial and resin bezel;
• GMC-2500-1A8: silver dial;
• GMC-2500G-9A: gold-toned dial and bezel.

The GAC-2500 range comprises:

• GAC-2500-1A: black;
• GAC-2500-3A: green;
• GAC-2500-7A: white;
• GAC-2500-9A: yellow.

CasioNaut: price list and product availability

The new GAC-2500 models are priced at €129.00, while the GMC-2500 models list at €249.00. All models are now available online and at official G-Shock retailers.

Initial thoughts

The CasioNaut nickname may stem from a resemblance to the Nautilus, but these new G-Shocks primarily evolve the brand’s own design language.

With the GAC–2500 and GMC–2500, Casio gives G-Shock’s construction a cleaner analogue look, retaining the link to the DW-5000C while introducing a new way to display and manage its functions.

(Photo credit: G-Shock)