Catalina Channel mushroom kayak: man paddles 26 miles in a giant fungus
Most mushrooms end up on toast. Sam Shoemaker grew one into a 12-foot kayak and paddled it 26 miles across California's Catalina Channel – and Guinness World Records has now made it official.
Most mushrooms end up on toast. Sam Shoemaker’s ended up crossing the Catalina Channel.
The Los Angeles artist and mycologist has been named the Guinness World Records holder for the “longest solo journey by fungal mycelium boat”, after paddling a kayak grown from a single mushroom 42.43 km (26.37 miles) from Catalina Island to Cabrillo Beach in San Pedro. The crossing actually took place on 5 August 2025 and lasted just over 12 hours; Guinness announced the record on 10 November 2026.
AI illustration – the view from the yacht, imagined. Not the actual boat.
The 12-foot vessel was grown from Ganoderma polychromum mycelium – the root-like part of the fungus – packed into a fibreglass mould that Sam and his cousin Laza made from a second-hand kayak. It took seven weeks to grow, three more months of preparation and testing, and at one point a home-made rig that spun it “like a rotisserie chicken” so it dried evenly. Finished with shellac and beeswax, it weighs 107 lb (about 48.5 kg) and is entirely biodegradable. His first attempt, a 15-foot mushroom kayak, came in 2024.
The trip was no picnic, apart from the picnic: rough cross-swells early on, fears the boat might “snap in half”, then peanut butter toast with chilli flakes and a young fin whale tagging along for two hours.
AI illustration – the welcome party, imagined. (Spot Gaz, our gorilla, hiding somewhere in this picture.)
Would he do it again? Probably not in a mushroom, he told Guinness. Sensible. That’s a lot of risotto to lose at sea.
Reported by Guinness World Records (Katherine Gross, 10 Nov 2026; record page) and UPI (Ben Hooper, 12 Nov 2026). The crossing took place on 5 Aug 2025. Photo: Don Ramey Logan, CC BY-SA 4.0, via Wikimedia Commons. Illustrations: Gorilla Gazette / AI-generated.
