More than 1,000 people have taken on the Royal Marines Endurance Course in a bid to raise money for charity.
It is a rare opportunity for civilians to try one of the four Royal Marines' Commando tests, which training recruits need to pass in a week in order to receive their Green Berets.
The event raised funds for Devon Air Ambulance and The Royal Marines Charity, which supports wounded Marines and their families.
Jonathan Ball, the charity's CEO, said: "This is the only time in the year that civilians are allowed to use this Endurance Course.
"Even the Marines themselves don't do this until way on in their training!
"It is a special privilege to be able to meet the Marines in this way."
The 10km-course in Devon included all the obstacles potential Royal Marines face, from wading pools and pipes to the 'sheep dip', a muddy underwater tunnel.
The event itself started in 1990 and has raised over £5 million since.
The Royal Marines' recruit training is one of the longest training programmes of any combat troops in the world.
The Commando Tests include the Endurance Course, a 9-mile speed march, a Tarzan Assault course and a 30-mile speed march across Dartmoor.
If they pass all the tests they are presented with their Green Berets at the end of the speed march.