Episode 1

Eight young adventurers go to extremes to help the planet. Sixteen finalists battle for one of eight places on the epic Serious Ocean expedition.

To test how they cope with extreme adventure, the contestants are pushed to the limit over a gruelling weekend of auditions in Cornwall. The terrifying challenges include crawling through pitch-black tunnels and tightrope walking hundreds of metres above the raging sea.

Sailing through the night around Land's End also proves to be a stomach-churning experience.