The course has previously tested contestants from television show The Biggest Loser and members of 2009's Tough Bloke challenge.

It pushed even the toughest youngsters to the limit yesterday as they climbed through tyre mazes, leapt from ropes and crawled through water tunnels.

Jamboree adventure activities co-ordinator Kent Palmer said the day's activities gave a gentle - and occasionally not so gentle - push out of comfort zones.

"It's a challenge by choice and it does put a lot of the kids out of their comfort zones," he said.

"A lot of kids don't like to get dirty - some do. But most are happy by the end of it, they definitely conquer a few fears."

A dirty day in the mud was topped off by an appearance from NSW Governor Marie Bashir as she officially opened the jamboree at a ceremony in the camp's main arena last night.

Professor Bashir, who is also Chief Scout for NSW, reminded the assembled scouts of the traditions underpinning the jamboree.

"This gathering in Appin of scouts from across the world will continue to fulfil the vision of Lord Baden Powell in developing and strengthening the skills, the capacity for service and the bonds of friendship and loyalty which enrich one's life," she said.

"I wish you all a memorable and most successful jamboree."

Prof Bashir was followed by Sydney rock band Bluejuice, who wasted no time in sending a crowd of more than 10,000 wild with hits including ARIA-nominated track Broken Leg.

The 10-day jamboree's action-filled program continues today with outdoor and trade skills activities and trips to Jamberoo Action Park.