Tap the image to enlarge
Casio G-SHOCK GG-B100X-1A9ER Master Of G Mudmaster Orange Strap Watch - W17642
Ref. GG-B100X-1A9ER
Sits in Casio’s upper tier here — more premium than three quarters of the Casio watches we list, which start at £25.
Price range £25 to £919 across 129 Casio watches in stock.The GG-B100 series arrived in 2019 as Casio's answer to a specific problem: how to build a Mudmaster — already one of the more demanding instruments in the Master of G land line — with less dependence on petroleum-derived materials. This variant takes that further, using bio-based resins in the case components and strap in place of conventional plastics, while the bezel is built from a three-layer construction with carbon fibre woven through it. The jerrycan aesthetic of off-road vehicles is a deliberate reference point in the overall shape. At 51.3mm wide and just over 19mm thick it is a substantial presence, yet 93 grams is remarkably restrained for something this engineered. The carbon core guard structure accounts for that — the material doing the work of steel at a fraction of the weight. The mud-resistant button guards are prominent and intentional, designed to keep the controls operable in the conditions where a compass, altimeter and thermometer are actually needed rather than decorative. The bright orange strap reads clearly against working clothing and pairs with the Bluetooth link to the Casio app, which adds altitude logging via the phone's GPS to the onboard sensor data.
- Reference
- GG-B100X-1A9ER
- Brand
- Casio
- Collection
- G-Shock
- Case size
- 51.3mm
- Case thickness
- 19mm
- Case material
- Stainless steel
- Case shape
- Round
- Dial
- Black
- Functions
- Stopwatch, Countdown timer, Alarm, Backlight, World time, Perpetual calendar, Bluetooth, Step counter, Compass, Thermometer, Altimeter, Dual display, Digital display
- Water resistance
- 200m
- Bracelet / strap
- Rubber strap
- Strap colour
- Orange
- Retailer
- F.Hinds
Additional specifications
- Lug-to-lug
- 55.4mm
Learn more about Casio
Tadao Kashio founded Kashio Seisakujo in Tokyo in 1946 as a machine shop. The company's first success was a finger ring that held a cigarette, and its second was the 14-A of 1957 — the world's first all-electric compact calculator, which used solenoids rather than gears.
Casio entered watchmaking in 1974 with the Casiotron, a digital watch with an automatic calendar that knew the varying lengths of months. The company approached watches as an electronics manufacturer rather than a horological one, and that difference produced the G-Shock.
The G-Shock came from a single engineer, Kikuo Ibe, who broke a watch his father had given him and set out to build one that could not break. The specification was three tens: survive a ten-metre drop, ten bars of water pressure, and ten years of battery life. It took over two hundred prototypes, and the solution was suspending the module inside the case on a cushioned internal structure rather than mounting it rigidly. The DW-5000C shipped in 1983.
It became one of the most durable product designs in any category, adopted by militaries, emergency services, and skateboarders alike, and Casio has since added solar charging, radio and GPS timekeeping, Bluetooth, and full-metal and carbon variants.
Casio also produces the Edifice, Pro Trek, and Oceanus lines, and remains an independent Japanese public company.
- 1946
- Tadao Kashio founds the company in Tokyo.
- 1974
- The Casiotron is Casio's first digital watch.
- 1983
- The G-Shock DW-5000C survives Kikuo Ibe's three-tens brief.
- 1994
- The Frogman extends G-Shock to ISO dive certification.
Manufacturer’s guarantee
Best of 2 retailers
What the specifications mean
A mechanical watch built to be worn hard and got wet.
Strengths
- 200m water resistance, rated for actual diving
- 55.4mm lug-to-lug keeps the 51.3mm case wearable
- Luminous hands and markers for low light
- Second time zone for travelling
- One of Casio's more premium watches
Worth knowing
- 51.3mm is a large watch with real presence
- 19mm thick, so it will not disappear under a cuff
Compare alternatives
Watches from other brands at a similar price, style and size, so you can see what else your budget can buy.
| Specification |  GG-B100X-1A9ER |  I15202 |
|---|---|---|
| Price | £349 | £277 |
| Case size | 51.3mm | 48mm |
| Water resistance | 200m | 50m |
| Movement | Automatic | Automatic |
| Strap | Rubber strap | Rubber strap |
| This watch |
|
Your new watch
Frequently asked questions, and things you should know about this watch
Can I swim with it?
Yes. At 200m it is rated for swimming, snorkelling and recreational diving.
Will the glass scratch?
It can, over time. Mineral glass handles daily wear but will pick up fine scratches that sapphire would not.
Does it need a battery?
No. It is automatic — the motion of your wrist winds it, and there is no cell to replace.
Will it fit my wrist?
Lug-to-lug is 55.4mm, which suits wrists from roughly 18.5cm (7¼ inches) upward.
Lug-to-lug decides fit more than case diameter does.
Is it a men's or women's watch?
Listed as men's.
Cheapest place to buy
Both F.Hinds and Goldsmiths list it at £349, so choose on delivery and warranty rather than price.
Who are F.Hinds?
F.Hinds has been run by the same family since 1856 and is now in its fifth generation, with more than 115 shops across England and Wales. They are a member of the Responsible Jewellery Council and an Authorised Diamond Dealer.
You may also like
In stock, and close on style and price
