A 26-mile (48.1 km) journey across open water in a kayak made entirely from mushroom has drawn attention to the growing interest in natural alternatives to plastic. Artist and fungal materials researcher Sam Shoemaker paddled the handcrafted vessel from Catalina Island to San Pedro, California, marking one of the most ambitious uses of fungi-based materials in marine environments to date.
Shoemaker completed the 12-hour trip in early August using a boat grown from mycelium, the root-like structure of fungi. The lightweight, biodegradable material is being explored as a sustainable replacement for plastic, especially in products that often end up in oceans.
Equipped with only a compass, camera, walkie-talkie, and mobile phone, Shoemaker navigated open waters in a vessel weighing 107 pounds (48.5 kilos). The surface of the boat remained coarse and irregular — a natural result of the fungi’s growth process — but it held up throughout the journey. A built-in keel added balance during the crossing.
An unexpected encounter at sea
Roughly 3 hours into the trip, Shoemaker began to feel seasick, far from any visible shoreline. Then, something unexpected happened — a 50-foot (about 15 meters) fin whale surfaced near his kayak and followed alongside for nearly 3 miles.
Describing the moment afterward, Shoemaker called it “a psychedelic experience,” saying the whale’s appearance shifted the mood of the solitary expedition and gave him renewed energy to finish the paddle.
Family and supporters greeted him upon arrival on the mainland, viewing the event not just as a personal triumph but also as a public demonstration of what natural materials can achieve.
An American man crossed dozens of kilometers in a mushroom boat
U.S. artist and mycologist Sam Shoemaker paddled 42 kilometers in a kayak grown entirely from mushroom mycelium. The trip took 12 hours, and the boat held together without falling apart.
The kayak wasn’t assembled… pic.twitter.com/uAVkBdUr15
— NEXTA (@nexta_tv) September 9, 2025
Phil Ross, co-founder of MycoWorks and Shoemaker’s longtime mentor, described the crossing as “remarkable.” Ross has been at the forefront of mycelium research for decades and helped develop fungal-based products used in fashion, furniture, and medicine. He coined the term “AquaFung” to describe the mushroom material designed specifically for use in aquatic environments.
Unlike plastic or Styrofoam, Ross noted, mushroom-based materials break down naturally over time. “This acts like the stuff people hate washing up on beaches — but it disappears on its own,” he said.
A slow but promising shift
Shoemaker is only the second known person to pilot a mushroom vessel on water. In 2019, Katy Ayers of Nebraska gained recognition for building and paddling what remains the longest fungal canoe ever recorded. Ayers said many doubted the idea, including the biomaterial companies she contacted early on. But she pursued it regardless, driven by curiosity and determination.
Shoemaker began working with fungal materials in 2020 during his graduate studies at Yale. After years of experimentation, he built his first mushroom kayak in 2024. That initial version took nearly a year to grow and dry. The second, completed this past June, featured improvements in size and strength and was the one used for the ocean crossing.
While the project has captured imaginations, Shoemaker is cautious about overpromising. People like to think mushrooms will solve all the problems with plastic,” he explained. But this isn’t a magic fix. Making a boat from fungi is still very difficult and time-consuming.
Despite the hurdles, researchers and designers continue exploring how fungal materials might one day reduce the environmental impact of plastics, particularly in industries where pollution remains a major concern.