Casio's New Mudmaster Wraps Bioplastic in Magma — and Costs £800
Casio has added a magma-themed Mudmaster to its Master of G line, and it's heading to UK shelves priced at £800 — making it one of the most expensive polymer-cased G-Shocks yet. The GWG-B1000MG-1A9 launched in Japan in late May 2026 at ¥143,000 (around $910), with a global rollout confirmed and EU availability expected in June at €899.
The look
The design is built around volcanic imagery: a dial with red-orange accents, gold ion-plated metal parts meant to evoke glowing molten metal, and a band with a layered texture modelled on geological strata. The bezel and main case components are made from bio-based resin — plant-derived plastic sourced from materials like castor bean or corn, per Casio CSR global. Casio says the eco-friendly materials don't compromise the watch's shock, vibration, and mud resistance, and it still carries a 200-metre water resistance rating (20 bar).
The kit
The Mudmaster line has always leaned hard on sensors, and this model is no different. The GWG-B1000MG packs a triple sensor — digital compass, altimeter/barometer, and thermometer — alongside Bluetooth pairing to the Casio Watches app. A Location Indicator function uses your phone's GPS coordinates to point you back toward a saved waypoint, which is useful for anyone deep in the backcountry. Multi-Band 6 radio syncs the time automatically across six global time-signal stations.
Power comes from Tough Solar, which charges the battery from any light source. In complete darkness, the battery lasts six months under normal use or up to two years in power-saving mode. The sapphire crystal carries an anti-reflective coating, and dual Super Illuminator LEDs keep the dial readable in the dark.
Worth it?
At £800, this sits at the top of the G-Shock polymer range, above most Garmin Instinct and Suunto flagship models it competes with in the rugged-outdoor segment. The bioplastic angle is a differentiator, but Casio hasn't cited any third-party sustainability certification for the materials — something worth noting if eco-credentials are a purchase driver for you. The Casio UK listing shows the watch as coming soon, with no confirmed ship date beyond the Japan launch window. If the aesthetic clicks — and for a certain kind of outdoors enthusiast, it very much will — there's a lot of genuine capability packed in here.
