Buying a rugged G-Shock is easy. Deciding whether you need one of the largest and most specialized models in the catalog is harder. The new Casio Master of G Sea Frogman GWF-D1000BC-1JF is built around diving functions rather than just dive-watch styling, with ISO 200-meter diving water resistance, depth and temperature measurement, compass readings, dive logging, Tough Solar charging, and Multi-Band 6 timekeeping.
Price: ￥198,000 (Around $1,282)
Where to Buy: Casio Japan
Scheduled to arrive in Japan in September 2026, the GWF-D1000BC-1JF is priced at ¥198,000 including tax. At 59.2 x 53.3 x 18mm and 181g, it is a purpose-built tool watch, not a subtle everyday G-Shock.
The Diving Hardware Is the Point
The defining feature is not the black-and-tan colorway but the watch’s diving-specific hardware. Casio says the Frogman combines a stainless-steel and resin case, a highly sealed screw-lock case back, and a thick sapphire crystal to meet ISO standards for 200-meter diving water resistance. The crystal also has an anti-reflective coating on its inner surface.
Its depth sensor measures from 0 to 80 meters in 0.1-meter increments. In Diving Mode, the watch automatically begins and ends depth measurement at around the 1.5-meter mark and saves the session to its dive log.
The watch can store up to 20 dive records, including dive start date and time, dive duration, maximum depth, and minimum water temperature. It also provides a surface-interval display for up to 48 hours and an ascent-speed warning.
Those functions give the Frogman a more compelling reason to exist than simply looking like professional diving equipment. It is intended for people who want underwater information available from the wrist, not just the visual language of a dive watch.
Triple Sensor Hardware Covers Depth, Direction, and Temperature
Casio equips the GWF-D1000BC with Triple Sensor hardware for depth, direction, and temperature measurements. Temperature measurement ranges from -10 to 60 degrees Celsius in 0.1-degree increments, while the compass measures bearings from 0 to 359 degrees.
The compass also includes bearing memory, magnetic-declination correction, calibration functions, and automatic horizontal compensation. Casio specifies continuous compass measurement for 60 seconds in normal use and 20 seconds in Diving Mode.
The standard 16-direction display is not shown while diving, so the underwater compass implementation is not identical to the regular compass mode. Casio says its horizontal-compensation system is designed to help provide useful readings when a diver’s posture is unstable underwater, though real-world accuracy will still depend on conditions and correct calibration.
Tough Solar Helps Reduce Maintenance
Tough Solar charging and Multi-Band 6 radio-controlled timekeeping help keep the Frogman’s maintenance low. It receives calibration signals in Japan, North America, Europe, and China; without reception, Casio rates accuracy at plus or minus 15 seconds per month.
Casio estimates roughly seven months of normal operation from a full charge without additional light exposure, or about 23 months with power saving enabled. World time, tide and moon data, five alarms, a 100-hour stopwatch, a 24-hour countdown timer, and a white LED Super Illuminator round out a feature set that makes this more than a basic digital dive watch.
A Bracelet That Fits Over a Wetsuit
The GWF-D1000BC-1JF uses a composite bracelet made from metal and biomass plastic instead of the simpler resin straps found on other Frogman versions. The major resin components use biomass plastic, while the bracelet’s metal-and-resin construction is intended to balance strength and weight.
Its useful feature is a two-stage extension mechanism that lets the bracelet fit over a wetsuit. The clasp also includes a slide-adjustment mechanism for more precise sizing.
Casio says the composite construction is both strong and lightweight, although the finished watch still weighs a substantial 181g. The bracelet may reduce weight compared with a fully metal design, but this remains a large and heavy watch that will be very noticeable on the wrist.
The steel bezel uses a black DLC coating, while the front screws receive black IP treatment. Tan details reference tactical gear and contrast with the otherwise black case and bracelet. The color treatment is subjective, but the practical value of the bracelet extension, sapphire crystal, diving sensors, and ISO dive rating is easier to establish.
Who Is It For?
The Frogman makes the strongest case for divers and collectors who will use its sensor suite. If you want depth measurement, temperature information, compass data, automatic dive logging, solar charging, radio-controlled timekeeping, and an ISO-rated dive watch in one G-Shock, the GWF-D1000BC-1JF delivers an unusually concentrated collection of tools.
It makes less sense as a casual purchase. At 53.3mm wide, 18mm thick, and 181g, it is much larger and heavier than most everyday watches. Its ¥198,000 price also puts it far beyond mainstream digital G-Shock territory, meaning casual buyers would pay a considerable premium for capabilities they may rarely use.
Price: ￥198,000 (Around $1,282)
Where to Buy: Casio Japan
For anyone who simply wants G-Shock toughness and strong water resistance, less expensive models will handle the basics. But for Frogman collectors and divers who will use its depth gauge, compass, water-temperature readings, dive logs, and wetsuit-ready bracelet, the GWF-D1000BC-1JF has a purpose well beyond its intimidating dimensions.
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