Membership of the Scout Association in Britain is rising at its fastest rate for nearly 40 years, as new activities and a "cool" chief scout attract record numbers of teenagers.

Its ranks swelled by 16,500 last year, the biggest number of new recruits since 1972, taking total membership to almost 500,000 nationwide, the Association reported.

The largest uptake has been among teenagers, a 26 percent rise since 2001.

The obligatory woggles, neckerchiefs, caps and three-fingered salutes are still part of the package, but the organisation has enjoyed an image boost with the appointment of TV adventurer Bear Grylls as Chief Scout last year.

"It's fantastic to witness such a huge surge in scouting and it is proof that it is appealing more and more to teenagers," he said.

"Scouting is empowering, wild and fun, and offers so many adventure-based activities for young people and adults alike."

Scout chiefs have also put down the surge in new members to the lure of high-energy adventure sports alongside more traditional skill-badge earning activities.

Numbers have risen for five years on the trot after declining between the mid-1970s and 2000.

The scout movement offers rock-climbing, abseiling, canoeing and alternative sports like "zorbing" -- being put inside an inflatable ball and rolled down a hill.

The rise comes as many schools and other groups have cut back on outdoor activities for fear of being sued in case of an accident.

Grylls, who was voted in one poll the seventh coolest British man in 2008, has set himself the goal of increasing the number of activities offered to 200 and raising the number of adult volunteers during his five-year term.

The movement says waiting lists to join are at an all-time high, with an extra 33,500 young people unable to enrol because of a lack of adult volunteers.