The two new Casio references reported in September 2026, the GWF-D1000BC-1JF Frogman and the GWG-B1000-1A3JF Mudmaster, are documented as Japan releases. Reporting from September 8, 2026 does not confirm US availability, US pricing, or a US release date for either model. Only the Frogman is described with sapphire crystal, and that claim applies to the Frogman alone.
What the September 2026 report actually establishes
Gizmochina’s September 8, 2026 report is the main source for the new models. It names two Japan-market references and gives their yen prices:
- Frogman GWF-D1000BC-1JF: ¥198,000 in Japan.
- Mudmaster GWG-B1000-1A3JF: ¥132,000 in Japan.
These are Japan prices as published in that report. They are not US list prices, and they should not be converted to dollars as if they were US retail prices.
Why the US arrival claim is not supported yet
Casio’s US product pages describe existing collection models, not the two September references. The US Master of G page covers the GWG-B1000 family and the US Frogman page covers its own set of models. Neither, as reviewed, lists the GWF-D1000BC-1JF or the GWG-B1000-1A3JF. Until Casio America publishes a model-specific listing, announcement, or retailer listing with the exact suffix, a US arrival should be treated as unconfirmed.
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![CASIO GWG-2000-1A1JF [G-Shock Carbon MUDMASTER Radio Solar Triple Sensor]Shipped from Japan](https://m.media-amazon.com/images/I/51QajkabT4L._SL160_.jpg)
- Item Trademark: Casio
- Item Category: Watch
- Manufacturer: CASIO
- Manufacturer: CASIO
The June 4, 2026 Gizmochina report is sometimes read as evidence of US availability for a Mudmaster. It concerns a different reference, the GWG-B1000MG-1A9, which that report says was available in the US for $900. That was a dated report about a different model. It does not show that the newer GWG-B1000-1A3JF is sold in the US and it is not a current price.
The two new Japan models
Frogman GWF-D1000BC-1JF
The September report is the only source for this model’s specifications, and it describes the following:
Rank #2
- Construction Shock-resistant; vibration-resistant Performance 200-meter water resistance, low-temperature resistance (-10C / 14F) Radio Frequencies 77.5 kHz (DCF77: Germany); 60 kHz (MSF: UK); 60 kHz (WWVB: USA); 40 kHz (JJY: Fukushima, Japan) /
- Countdown Timer Measuring unit: 1 second (maximum 60 minutes) Alarm 5 independent daily alarms; hourly time signal Other Functions Full auto-calendar; 12/24-hour format; battery level indicator; button operation tone on/off; full auto double LED back
- Power Source Tough Solar power system (high-capacity solar-charging system)
- Radio Wave Reception Automatic reception up to six times a day (except for use in China: up to five times a day); manual reception Digital Compass Measures and displays direction as one of 16 points with the second hand; measuring range: 0 to 359;
- Altimeter Measuring range: -700 m to 10,000 m (-2,300 ft to 32,800 ft.); measuring unit: 1 m (5 ft.); manual memory measurements (up to 30 records, each including altitude, date, time); auto log data (high/low altitudes, cumulative ascent and descent
- ISO-standard 200-meter water resistance
- Sapphire crystal
- Depth gauge to 80 meters, displayed in 10-centimeter increments
- Digital compass with automatic horizontal compensation and a thermometer
- Metal-and-resin composite bracelet with a two-stage extension
- DLC-coated stainless steel bezel and a screw-lock case back
- Tough Solar charging and Multiband 6 time signal reception
The depth gauge is the main functional difference from the standard Frogman line, which Casio US positions as an ISO-rated dive collection.
Mudmaster GWG-B1000-1A3JF
The same report describes this model with Carbon Core Guard construction, dust, mud and vibration resistance, an altimeter, barometer, thermometer, compass, Bluetooth connectivity, and functions through the Casio Watches app. The report does not state that this reference has sapphire crystal, and it does not give a water-resistance rating. Readers should not assume either feature from the Frogman’s specification.
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- MUDMASTER Built for Extreme Environments – Rugged construction is engineered to resist mud, dust, shock, dirt, and debris, making the GG1000-1A5 ready for demanding outdoor conditions.
- Twin Sensor Compass & Thermometer – Built-in digital compass measures direction across 16 points and 0° to 359°, while the thermometer measures temperatures from 14°F to 140°F (-10°C to 60°C).
- Shock Resistant & 200M Water Resistant – Legendary G-SHOCK toughness combines shock-resistant construction with 200-meter water resistance for dependable performance during outdoor adventures and demanding work.
- Super Illuminator LED Backlight – High-brightness white LED backlight features an auto light switch, selectable 1.5- or 3-second illumination, and afterglow for improved visibility in low-light environments.
- World Time & Advanced Timekeeping – Includes world time across 31 time zones and 48 cities, a 1/100-second stopwatch, 60-minute countdown timer, 5 daily alarms, snooze alarm, and full auto-calendar through 2099.
Sapphire crystal: what is documented and what is not
Sapphire is documented for one new model only. For the Frogman GWF-D1000BC-1JF, the report says sapphire crystal is fitted. For the Mudmaster GWG-B1000-1A3JF, the report is silent. Among US-listed references, Casio’s US MR-G Frogman page describes the MRGBF1000R-1A with sapphire crystal, ISO 200-meter water resistance, solar power, Bluetooth, and Multiband 6. That is an existing model, not one of the September releases.
Comparison: new Japan releases and established US-market references
| Reference | Market status (as reported) | Crystal | Water resistance | Published price |
|---|---|---|---|---|
| Frogman GWF-D1000BC-1JF | Japan release, reported September 8, 2026; US availability not confirmed | Sapphire crystal | ISO-standard 200 m | ¥198,000 (Japan) |
| Mudmaster GWG-B1000-1A3JF | Japan release, reported September 8, 2026; US availability not confirmed | Not stated | Not stated | ¥132,000 (Japan) |
| Frogman MRGBF1000R-1A | Listed on Casio’s US MR-G Frogman page | Sapphire crystal | ISO 200 m | Not stated |
| Mudmaster GWG-B1000MG-1A9 | Reported available in the US, June 4, 2026 | Not stated | Not stated | $900 (June 2026 report; may have changed) |
The two Japan rows and the US rows are different references. The table is a comparison of what each source states, not evidence that the Japan models are sold in the US.
Rank #4
- Enjoy both fearless adventure and a comfortable fit with this tough and rugged Master of G Mudmaster flagship timepiece
- This analog-digital combination watch delivers more comfortable fit and outstanding durability with a robust exterior incorporating a guarding structure built with metal components
- The comfortably sized GWG-B1000 features a metal exterior crafted with high-precision forging techniques and a carbon fiber-reinforced resin case that offers high strength and outstanding durability
How the two lines differ
Casio’s US Master of G collection describes the GWG-B1000 family as the Mudmaster flagship, built for land use, with vibration resistance, Multiband 6, Bluetooth, Tough Solar, and altimeter, barometer, compass and thermometer functions. Casio’s own collection copy frames the line this way: “Whether on the land, in the sea, or in the air, the G-SHOCK Master of G collection provides you with critical information for outdoor adventuring, mountaineering, backpacking, and military or police purposes.”
The Frogman line is the dive-oriented range, with an ISO 200-meter rating across its US collection. If you need water resistance and a dive-style depth gauge, the Frogman is the relevant line. If you need terrain-oriented sensors and vibration resistance, the Mudmaster is.
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Best Value
- Featuring a Black Band, Black Case, Scratch Resistant Mineral Crystal
- International products have separate terms, are sold from abroad and may differ from local products, including fit, age ratings, and language of product, labeling or instructions
- Original box and packaging: Watch back, but it might be different in the printed image
- Scratch resistant mineral
How to verify US availability before buying
- Search Casio America’s G-SHOCK US site for the exact model number, including the suffix. The Japan releases end in -1JF and -1A3JF, which are not the same as US model codes such as MRGBF1000R-1A or GWG-B1000MG-1A9.
- Check whether a product page exists for the exact reference and whether it lists a US price in dollars.
- Check authorized US retailers for the same model number. A listing for a similarly named watch with a different suffix does not confirm the new reference.
- If a listing shows a Japan-market model, confirm the seller’s country and warranty terms before purchase.
The headline’s claim that the new Mudmaster and Frogman “finally arrive in the US” cannot be verified from current reporting. The exact references, prices and sapphire claims above are the figures on record.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
