Most watch launches happen in a showroom with a tray of drinks. G-SHOCK's new one starts with an abseil. To launch the new MUDMAN GDG-B100, G-SHOCK UK is throwing a one-night rave 1,375 feet below ground in Cwmorthin Slate Mine in Eryri, North Wales, on Thursday, October 15, 2026, according to Casio's official MUDMAN page.
Getting to the dance floor is the whole bit. Casio says guests will go down through dark tunnels and waterlogged passages, cross underground ravines, ride zip lines and abseil down rock faces before they reach the chamber. Drum and bass legend Roni Size is on the decks, and the official poster adds DJ Nav. Casio also says a sound experiment will push parts of the set into the slate, record the vibrations moving through the rock, water and mud, and feed them back into the mix. So the mountain is basically a guest feature.
Spots were handed out by a public ballot that closed October 9, so this one's for the lucky few. Everyone else can listen in. The set will air on G-SHOCK Radio on the night (the poster says tune in at 9 PM), and the full performance will be posted afterwards. T3 reports that the people who make it down get first access to buy the watch before its wider release, and that G-SHOCK will submit footage to try to get it recognized as the world's deepest underground rave. Nothing is official on that record yet.
The watch itself is built for exactly this kind of nonsense. The GDG-B100 sits in the Master of G line and has a bumper guard design inspired by off-road vehicles and survival gear, with shock, dust and mud resistance. It also gets a sharp MIP LCD screen, a red LED backlight that's easier on your night vision, a step tracker, Smartphone Link, and run tools like distance, pace, lap memory and an interval timer. A USA Today report carried by the South Wales Argus puts it at £200.
Our take: G-SHOCK has been the "drop it off a building" watch for more than four decades, so a launch where you have to survive a slate mine to buy one is very on brand. Roni Size won the Mercury Prize with Reprazent in 1997, the same year that mine closed, which is a fun coincidence. We'll stick to listening from the couch.
The details: G-SHOCK MUDMAN GDG-B100 launch rave with Roni Size, October 15, 2026, Cwmorthin Slate Mine, Eryri, North Wales. Ballot closed October 9. Broadcast live on G-SHOCK Radio, full set posted afterwards.
Update, Wednesday, October 14, ~9:35 PM ET: Tomorrow is the night. Roni Size and DJ Nav go 1,375 feet under Cwmorthin for the MUDMAN GDG-B100 launch, with the set on G-SHOCK Radio at 9 PM. Ballot winners get first crack at the watch (~£200); ballot closed October 9. Everyone else can listen from ground level.
At ONENESS: The GDG-B100 isn't in our lineup right now. Browse Casio at ONENESS, and see our story on the G-SHOCK MR-G in blue sapphire.
Photos and event details via Casio G-SHOCK UK. Additional reporting via T3, Notebookcheck and the South Wales Argus.
