G-Shock’s newest aviation-themed Gravitymaster is a Grasp of G, that means it’s made for the harshest environments.

Casio launched the brand new Gravitymaster GRB300 assortment in 2024 with three variations (GRB300-1AGRB300-1A4, and GRB300-8A2). This assessment focuses on the GRB300-1A — which has a sporty, traditional black, white, and purple mixture.

G-Shock Gravitymaster GRB300-1A

G-Shock says the Gravitymaster is “a chunk of aviation-inspired skilled gear” and accordingly the case takes cues from plane fuselages, the dial is designed for top visibility, there’s a chronograph that may show elapsed time, twin illumination is offered for lowlight cockpit circumstances (lume and LED), there’s a twin time show, and the digital crown which permits for guide setting of the time — are all helpful to a pilot.

G-Shock Gravitymaster GRB300-1A

The Gravitymaster GRB300 case measures 54.7 mm x 15.7 mm (48 mm with out the crown guards) and 59 mm (lug-to-lug). Its sizable dimensions enable for a extremely legible dial — wonderful legibility is a prerequisite of any aviation-focused watch. 4 massive flat pushers enable the watch capabilities to be operated extra simply than with smaller, recessed buttons. The 7.5 mm diameter digital crown (non-locking) is massive sufficient to be adjusted simply, and the crown guards don’t intrude. Regardless of the scale, the Gravitymaster GRB300 weighs simply 71 grams. I’d advocate it to folks with medium to bigger wrists, or people who love bigger watches.

G-Shock Gravitymaster GRB300-1A wristshot

The case, bezel, and band are made with bio-based resin, a cloth anticipated to assist cut back environmental affect. A Carbon Core Guard construction for the inside case delivers excessive shock resistance, rigidity, and corrosion resistance. The carbon fiber-reinforced resin case and the seamless bezel design have been impressed by next-generation plane and have an aerodynamic aesthetic.

G-Shock Gravitymaster GRB300-1A

Casio gave the Gravitymaster Bluetooth performance that permits the wristwatch to hook up with your smartphone and mechanically alter the time for you. Moreover, as soon as linked to the Good Hyperlink through the Casio Watches App, you need to use the flight log reminiscence operate to document the present location and time. The app additionally permits you to management quite a few different capabilities, together with the dual-time operate (with AM/PM indicator).

G-Shock Gravitymaster GRB300-1A

The rotary disc indicator on the 9 o’clock place makes use of a dual-coil motor to make sure easy rotation. The indicator rotates when the highest left button is pushed (which modifications modes), indicating a change between AL (alarm), TR (countdown timer), and ST (stopwatch/chronograph) modes. It might be cool to see the disc rotating repeatedly, or each 20 seconds, however the battery life would seemingly endure an excessive amount of to make {that a} viable possibility.

G-Shock Gravitymaster GRB300-1A

The high-contrast show of the dial is supposed to evoke the look of a cockpit. Massive palms, massive indices (and Arabic numerals at 12 and 6), make studying the time simple to do at a look, a key design factor of any pilot watch. Being a G-Shock there’s numerous added performance as nicely, and although the dial is clear, a number of the fonts, akin to on the left facet of the 12’clock operate indicator (proper reveals the day of the week). I ponder if the day of ought to have been omitted in favor of higher optics for the operate indicator. In my use case, I’d have most well-liked that.

G-Shock Gravitymaster GRB300-1A lumeshot

Conventional painted-on luminous materials coats the hour and minute palms, in addition to the ten indices. The 12 and 6 o’clock weren’t given a luminous remedy, although it might have actually improved low-light visibility. That stated, there’s additionally a white LED gentle that may be activated on the press of the button.

G-Shock Gravitymaster GRB300-1A

A stainless-steel caseback, engraved with the “SHOCK RESIST” defend, the G-Grasp mark, and different related specs, akin to a 20ATM water resistance ranking (200 meters), is secured to the caseback through 4 conventional screws which can be slotted for a flat or Phillips head screwdriver.

G-Shock Gravitymaster GRB300-1A

To avoid wasting energy, the watch mechanically stops the palms when left at midnight. Saving further energy, the minute hand solely strikes each 10 seconds. Whole run time is roughly 5 months on the rechargeable battery (operation interval with regular use with out publicity to gentle after cost) and 18 months on the rechargeable battery (operation interval when saved in complete darkness with the ability save operate on after full cost).

G-Shock Gravitymaster GRB300-1A caseback

Functionally, the Gravitymaster has a stopwatch (with 1-second accuracy, in a position to measure as much as 24-hour intervals, each elapsed and cut up instances), a countdown timer (with a 1-second readout that may countdown from as excessive as 24 hours), an alarm that may be turned on and off, all chosen with the mode button. Moreover, the Gravitymaster presents a twin time operate (with an AM/PM indicator that may be simply managed by the Casio Watches app), a date show and day indicator (that’s correct till the 12 months 2099), and a telephone finder.

G-Shock Gravitymaster GRB300-1A


The Gravitymaster GRB300 assortment encompasses a quartz module that recharges mechanically through solar energy (each synthetic and pure gentle), Bluetooth time computerized syncing as soon as linked to the Casio Watches app, correct to -15/+15 seconds monthly even when not linked to Bluetooth.

Total the dial is obvious and extremely legible, which is an absolute requirement of a pilot-focused watch. And there should not too many capabilities to the purpose that it will get overwhelming.

Casio has enhanced the look, performance, and sustainability of its Gravitymaster —  a dual-time, pilot-style watch, for the smartphone age.

The retail value is $300. Study extra at G-Shock.




Reference: GRB300-1A

Yr: 2024

Whole Weight: 71 grams

Case Materials: carbon/bio-based resin/chrome steel

Case Diameter: 54.7 mm (48 mm not together with crown guards)

Case Thickness: 15.7 mm

Lug-to-lug: 59 mm

Crown Diameter: 7.5 mm (non-locking, protected by crown guards)

Glass: mineral crystal (armored)

Motion: Japanese Quartz Module 5719

Depth Score: 200 meters

Strap: 22 mm/20.5 mm