Commando Challenge sheep dip

Although the last two years have seen a boom in obstacle course races, they really are nothing new. There’s a lot of hot air being blown about who invented this sport and who is supposedly copying whom but, at the end of the day, all of these events are ultimately inspired by something that has been used in military training since the year dot.

One of the most legendary military training facilities in the UK is the Commando Training Centre Royal Marines (CTCRM) in Lympstone near Exeter, and a couple times every year “civvies” have the opportunity to run the course at Commando Challenge. Last weekend I was one of those lucky civvies!

Water Run

Before every Royal Marine can be awarded their green beret they must complete CTCRM’s endurance course, which involves a 4km assault course and a 6km run back to the base. If that sounds easy, try doing it in full kit with a 35 pound bag, carrying a rifle and then having to hit 6 targets out of 10 once you’re back at the base - all within 71 minutes! While taking part in the race this weekend I saw a few of the recruits taking their test and it looked like hell. Just the thought of running in army boots is unpleasant enough, but carrying all of that kit around when you’re soaking wet must be crippling.

Today we would be running an extended version of the course. At 17km we would be running from the base to the assault course and then running back again. Although it’s longer than the Marine’s test, we’d be doing it in running shoes and shorts - it was a totally different game!

If you need a break from words, check out this video I took of the course (don’t worry, there’s plenty more reading to be had afterwards):

Just before heading out on the course I bumped into Ed, a fellow obstacle course regular and, in a way, my friendly nemesis. Back at Nuts Challenge in March, having being ahead of of Ed for near-on 4 hours, he pipped me to the post in the last lap and became the first of only six people to finish the course. Although Ed will play down his ability - he’s a machine! As I lined up alongside him at the start line I knew I wouldn’t get away with ambling around this course, both of our competitive sides would be spurring us on.

The first 6km were mostly on roads and gravel as we headed out towards Woodbury Common and the legendary assault course. Ed forced an uncomfortably brisk pace, even though he kept on insisting that it was me pushing him on! Along the way we past a series of Royal Marine veterans, who were all super cheery and many of them shouted “Here come the yellow devils”, as Ed and I were both wearing our yellow Mudstacle vests... available on a website near you 😉

Commando Challenge Tunnels

The obstacle course itself was like nothing I’ve run before. The path winded over hills, sand, pebbles, bogs and rivers. In many places it cut into deep trenches and I really started to feel like I was running in historic footsteps. Thousands of the world’s most elite troops had pushed through those trenches for decades in preparation for combat. The course was dripping in authenticity.

The first man made obstacle was a tunnel crawl. As I dived through the square wooden opening, everything went pitch black. I expected my eyes to adjust but they never did. In all of the obstacle courses I’ve run, I’ve never experienced a tunnel like that. It twisted and turned under the ground and I had to completely rely on touch as it extended into the nothingness. The rocky ground was very unforgiving and I attempted to bear crawl with my knees off the ground for as long as my core would allow, but it got way too tiring to keep that up for such a massive expanse. Finally seeing the light at the end of the tunnel was a real relief!

That wasn’t the last of the tunnels, there were several similar ones around the course as well as concrete “Smarties Tubes” part-filled with water, which were extremely tight for the larger frames of myself and Ed.

Girl in mud

The highlight had to be the “Sheep Dip” though. I remember seeing this on TV when I was a kid and it looked like my worst nightmare. It summarised everything that petrified me about military training... I was only around ten... and a pretty scaredy 10 year old at that 😀

The sheep dips are completely submerged concrete tunnels. As I approached the opening I was instructed to dive through and throw my hands out to be grabbed by the marine on the other side. I held my breath, dived into the tunnel and realised that I was completely helpless. The tunnel was tighter than I had imagined and there was very little I could do to propel myself to safety. I was completely reliant on the Marine pulling me through the other side and, although I’m sure it happened within milliseconds, it felt like an eternity until he made contact with me. He dragged me to the surface and I gasped for air. What a rush! It was amazing and, again, a completely new experience.

Sheep Dip

The obstacle course was a lot of fun but was over all too soon. To be honest though, at the pace we were whipping around, I was relieved to get back onto relatively flat ground so that I could try to manage my breathing and regain my composure. The 6km trot back to base felt like a long long way and I felt for those marines that had been taking their test earlier that day. As we crossed the line we were met with a very cheery Marine who congratulated us and handed over our medals - another well-earned memento to take pride of place in my collection.

At Commando Challenge you’re not going to have the most heavily-packed obstacle course, but if you want authenticity, there’s nothing like it. The tunnels are amazing and the sheep dip is completely unique. The terrain of the central course itself is just incredible and I really found my imagination transporting me into gritty old school army training. Although we took part in the 17km Endurance event, the 10km Marine Challenge is the norm. If you’d like to take part in this legendary test, the next event is happening this October. I’m half tempted to go back and try it out with the full military kit, pack and fake rifle. Hopefully see you there... I’ll be the one collapsed in a hedge by the side of the road!

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  1. LOL at the Sheep Dip! As you say, I remember seeing this is a kid and thinking of it as the ultimate brutality! I hope more races incorporate this into future races – I assume it was worse than Arctic Enema?

    • Ha! Yeh, it was a great experience. It’s not so much worse, just really different. Arctic Enema is more about the shock of the cold. With the sheep dip I just felt helpless and 100% reliant on the guy dragging me through. If they do incorporate it at other events, they had better make 100% sure they know what they’re doing!

      • Oh dear. I have just entered for this years 10K Marine challenge and looking at the sheep dip, I started panicking and my heart started racing. Not fond of water unless its in a swimming pool! What can I do to prepare myself for this? And those very long dark tunnels just don’t look good, I hope to Mercy they are not in the 10K ? I am a novice and tried RockSolid last weekend. Absolutely loved it but what can I do to train well for this 10K ? Thank you from a 45 year old body with a 10 year olds enthusiasm 🙂


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