A former Royal Marine shows how to make it through an obstacle course
I’m waist-deep in thick, malodorous sludge. But right now the pong is the very least of my worries: a 6ft 4in former Royal Marine is bellowing at me from the riverbank.
“Spread out your body so there’s more surface area,” Brian Adcock orders, “then I can haul you in when you’re within range.” This sluggish, squelchy wading towards safety is the result of a failed, and deeply inelegant, attempt at a suspended commando crawl on an obstacle rather menacingly named The Chasm.
After losing balance, I had flipped off a horizontal rope two metres above the swamp-like waters. Following what seems an age, I manage to heave my body — heavier due to the now-sodden combat uniform I’ve been issued with — back on terra firma.

“Well done, good effort,” says Adcock, clapping my back with his spade-like hand. “You can take a chuck up for that.” Seeing my confused expression — even between the streaks of camouflage paint daubed on my face — the 45-year-old explains: “In Royal Marine parlance, that means give yourself a round of applause.”
Even though I am soaked through and stinky, the 6km obstacle course, studded with 15 challenges, is proving fun. Adcock explains that to master the commando crawl, my vertically pointed left leg should be more relaxed, “acting as a keel” while I shuffle along the rope with my hooked right leg pumping, piston-like, in unison with my arms.
Our lesson is taking place in the grounds of Hever Castle in Kent, where Adcock is holding an obstacle course event called Commando Series. It is a picturesque setting — the estate was the childhood home of Anne Boleyn — but with the dreaded Sheep Dip and a 12ft wall still to overcome, this is no time to lose my head.
Obstacle course racing (OCR) is a fast-growing sport. While there are no official figures for the UK, there were 1,370 events in the US last year, with about five million participants — up from 354 events in 2012. The second annual world championships took place in Ohio last month, encompassing eight miles of hellish competition for the most hardy.
Adcock, who is used to organising mass participation events after being event director for the Millennium Youth Games and establishing the popular Castle Triathlon Series in 2009, says the UK can add something unique to the sport. “It may sound a bit arrogant but Royal Marines generally do it better than most. After all, assault courses were — and still are — used to prepare elite soldiers for battle.”
The obstacles are based on those that the original British commandos used at Spean Bridge, a godforsaken place in the Highlands near Fort William, during the second world war. Winston Churchill had seen Boer commandos using guerrilla warfare against British troops when he was a young war correspondent. After Dunkirk, he copied those tactics and mobilised an elite group of soldiers to boost morale by creating little pockets of chaos in occupied Europe.
“Ultimately, from a commando perspective, obstacle courses make sure that your bloke is in good shape when it comes to pulling the trigger, so he can best take aim and kill somebody,” explains Adcock. “That’s the root of OCR. Of course, we are not going around with a weapon and a 30kg pack on our backs but it’s fun and brings out the kid in a lot of people.”
Adcock himself endured 14 months of gruelling training at the Royal Marines’ commando training centre in Lympstone, Devon, in what he calls a “seminal” period of his life. He then served in the marines for seven years, latterly as a helicopter pilot, though he isn’t allowed to divulge any details. For two years he held the record for the notorious Tarzan assault course at Lympstone. (It starts with a death slide, concludes with a rope climb up a 30ft near-vertical wall, and should be completed in “full fighting order” — ie, all the kit.)
As we approach the monkey bars, I eye the horizontal ladder above our heads with trepidation. Adcock barks instructions as I clumsily swing across the bars with more sludge below. “Keep your lower body as still as possible,” he suggests. I obey, and find it quicker to power from pole to pole.
I’m relieved at getting this far, having prevailed over another commando favourite, the Smarty Tubes, by pulling myself along with my thrusting elbows. I’ve survived the Catacombs of Doom, and conquered Peter’s Pool — a 30m-wide clay pit — neck deep in chilly, murky water.
I have slid, slipped and sloshed my way round the course. Occasionally we have come “under fire”, with smoke bombs, explosions and replica gun shots. Ultimately, obstacle courses make sure your bloke is in good shape when it comes to pulling the trigger Nonetheless, I still feel daunted as I face the last two obstacles.
The Sheep Dip is a liquid filled, trough-like structure similar to the ones used to remove sheep’s parasites and contains a two-metre long, submerged drainage pipe. As I tentatively enter the water, Adcock tells me to put my hands, thumbs up, at the top of tunnel I’m about to dive through. That, and not to kick when horizontal in the water so that the commando to my rear can shove me to the other side. I dive on the count of three, whizzing along the narrow pipe. At the other end an instructor yanks me to the surface and orientates me.
The final obstacle is a 12ft wall. “It’s actually 13½ft,” says Adcock looking ahead. “Use the vertical rope, and the netting, leaning your body close to the face.” A 20-second, temple‑bulging clamber later, I’m on top of the wall, and feeling on top of the world. Gleeful yet weary, I can’t help but exhale a loud cheer.
As a reward for completing the route, Adcock hands me a cap comforter, an item worn by those second world war commandos. Not quite a green beret, but still symbolic of my achievement. Grinning, he adds: “You can take a chuck up.”
This article was first published in the Financial Times Weekend in November 2015