Tap the image to enlarge
Casio G-SHOCK GG-B100X-1AER Master Of G Mudmaster Black Strap Watch - W17640
Ref. GG-B100X-1AER
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 Mudmaster sits at the serious end of the Master of G line — the range Casio developed for people whose work or terrain makes an ordinary watch a liability. The GG-B100X is built around a Carbon Core Guard structure: a high-rigidity carbon case with a three-layer resin bezel carrying carbon fibre inserts, a design profile the retailer copy notes has been updated over older GG-B100 generations. The jug-handle bezel shape draws from the fuel jerry cans used on serious off-road vehicles, which sounds like marketing until you see it in person and the logic becomes obvious. At 51.3mm across and 55.4mm lug to lug, this is not a watch that hides. Yet at 93 grams it sits lighter than its dimensions suggest, because the bio-based carbon and resin construction carries far less mass than steel of equivalent bulk would. The sensor suite — compass, altimeter, barometer, thermometer, step counter — is paired with Bluetooth and the Casio app's Mission Log function, which stitches the watch's altitude data together with GPS route data from a paired phone, a genuinely useful feature rather than a specification for its own sake. The dual LED backlight illuminates analogue and digital displays together, so the watch is legible in full darkness without the awkward partial illumination that undermines some mixed-display designs.
- Reference
- GG-B100X-1AER
- Brand
- Casio
- Collection
- G-Shock
- Case size
- 51.3mm
- Case thickness
- 19.4mm
- Case material
- Carbon
- 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
- Black
- 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 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
- 19.4mm 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-1AER |  010-03020-03 |  DZ4629 |
|---|---|---|---|
| Price | £349 | £430 | £289 |
| Case size | 51.3mm | 50mm | 49mm |
| Water resistance | 200m | 100m | 50m |
| Movement | Quartz | Quartz | Quartz |
| Strap | Rubber strap | Silicone strap | Stainless steel bracelet |
| 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?
Yes. It is quartz, so expect a battery change every two to three years at a jeweller.
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
