It seems Prince William was keen to be part of the action as he watched teenagers abseil at Narrow Neck Lookout in the Blue Mountains.

His countryman James Bond definitely would have approved.

Dressed in a smart jacket and trousers but not a Bond-style bow tie, Prince William came within centimetres of falling from a 100-metre cliff face in the NSW Blue Mountains on Thursday.

The Duke and Duchess of Cambridge were at Narrow Neck Lookout, a spectacular vertical cliff at Katoomba that plunges 100 metres to the lush bush below.

As he watched abseilers dropping down the cliff, Prince William stepped to within centimetres of the edge to have a really good look out, without wearing a safety harness.

“He took a bit of a lunge and a few people held their breath, gasped and readied their hands to grab him,” said Damien Cooper, manager of the Blue Mountains Youth Service.

“He was fine, of course, he knew what he was doing. I think his military background prepared him well for it.”

Tim Williams of the Blue Mountains Adventure Company added: “He was very calm on the edge; he didn’t worry about the safety briefing to stay a fair distance back.

“He just stepped up to have a cool look over.

“He said it would be nice to come back another time and have a go himself.

“They were both keen, it was just their attire that held them back.

“It’s a bit difficult to abseil in a suit and dress.”

James Bond would no doubt disagree with that.

Nonetheless, Prince William and the Duchess departed Narrow Neck Lookout having left onlookers with a real sense of derring-do.

The couple met a group of local teenagers who are members of the Mountain Youth services Adventure Program.

The youngsters demonstrated a range of adventure activities, including problem solving activities and games.