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Casio Mudmaster 58.5mm Mens Watch Black
Ref. GWG-B1000-1AER
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 line has been Casio's answer to a specific problem since 2015: how to build a G-Shock that functions reliably when the environment is actively trying to stop it. Mud, sand, vibration and magnetic interference are the design brief, not afterthoughts. The GWG-B1000 is the current flagship expression of that thinking, sitting above the GWG-2000 it evolved from, with a reworked Carbon Core Guard structure that trims the profile without softening the protection. The cylindrical steel buttons are sealed with gasket fittings to keep particulate matter out of the mechanics, and αGEL components inside the chassis absorb vibration before it reaches the module. At 58.7mm lug to lug, this is an unambiguously large watch, yet the integrated lugs taper down over the wrist in a way that distributes the 114 grams evenly enough that it does not read as heavy in wear. The steel guard components are finished in DLC, which keeps the whole thing visually coherent against the bio-based resin case. Timekeeping is handled by calibre 5713, which corrects hand alignment automatically after shock or magnetic interference and synchronises via both Multi-Band 6 radio and Bluetooth — meaning it is accurate without ever requiring the owner to intervene. The strap accommodates wrists from 145mm to 215mm and fastens with a dual-prong steel buckle, which holds more securely under repeated use than a single-prong will.
- Reference
- GWG-B1000-1AER
- Brand
- Casio
- Collection
- G-ShockCase Size: 52
- Case size
- 58.5mm
- Case thickness
- 16.2mm
- Case material
- Resin
- Case shape
- Round
- Dial
- Black
- Crystal
- Sapphire
- Movement
- Solar
- Calibre
- 5713
- Functions
- Stopwatch, Countdown timer, Alarm, Backlight, World time, Solar powered, Radio controlled, Bluetooth, Compass, Thermometer, Altimeter, Dual display, Digital display, Radio-controlled
- Water resistance
- 200m
- Bracelet / strap
- Rubber strap
- Strap colour
- Black
- Clasp
- Buckle
- Lume
- Luminous
- Retailer
- Goldsmiths
Additional specifications
- Lug-to-lug
- 58.7mm
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
What the specifications mean
A watch built to be worn hard and got wet.
Strengths
- 200m water resistance, rated for actual diving
- 58.7mm lug-to-lug keeps the 58.5mm case wearable
- Sapphire crystal, which resists scratching
- Luminous hands and markers for low light
- Second time zone for travelling
Worth knowing
- 58.5mm is a large watch with real presence
- 16.2mm thick, so it will not disappear under a cuff
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?
Unlikely. Sapphire is second only to diamond in hardness and shrugs off everyday marking.
Does it need a battery?
No. It charges from light, and the cell behind that is designed to last a decade or more.
Will it fit my wrist?
Lug-to-lug is 58.7mm, 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
Goldsmiths is the only UK retailer we track stocking this reference, so there is nothing to compare it against today.
Who are Goldsmiths?
Goldsmiths has been selling watches in Britain since 1778 and is part of the Watches of Switzerland Group, which is listed on the London Stock Exchange. They are an authorised dealer, so a watch comes with the manufacturer’s own warranty.
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