learn to open water swim confidently with open water coaching sessions, swim analysis and dry land exercises to improve your open water swimming & pool swimming



The biggest fear most swimmers and especially newcomers to triathlon have is swimming in the open water swimming. With most longer distance triathlons having the swim in open water and the increasing popularity of the open water swimming events it pays to have valuable experience of open water swimming. With Mark’s vast experience of open water swimming and long distance triathlons he can help you learn how to feel relaxed and perform at you best for these types of events or if you just water to open water swim for fitness or fun. Mark Kleanthous’s open water swimming coaching and one to one swimming sessions are available primarily in the south east of England and various open water venues. The open water swim coaching and personalised one to one swim sessions can help you with every aspect & teach you how to swim in open water and just a few of the skills I can help you with include.

  • Developing a relaxed breathing technique.
  • Mass starts swimming.
  • Learn how to swim efficiently around Buoys.
  • Treading water & correct sighting techniques.
  • Swim relaxed & efficient swimming in a straight line.



Confirmed venues for 2016 are as follows although by all means if you have access to other open water swim areas in the locality then please contact me to discuss options and fees as I may be able to travel to your venue. Please note that for this service there may be an additional fees for travelling to cover out of pocket expenses.

Venue 1

Box End Park Lake
Box End
MK43 8RQ

Facilities at Box End Park

  • 2 lakes
  • Lake 1 750m perimeter
  • Lake 2 has distance buoys every 200m total distance 1500m
  • Both are clean water & are tested

Box End Park is ideal for open water swimming cycling running & transition training. The venue has 1 km run markers so you can run 5km along a marked out run route on grass around the lakes. Off road cycling is also possible or you can cycle on quiet rural country lanes or run on the road. This lake has changing rooms and hot shower facilities along with a cafe, restaurant & bar for drinks and food for all budgets.

Venue 2

My second open water swimming venue is a secluded lake at a secret location south of Milton Keynes.
No fisherman No Boats No swimmers training. This lake is only available for One 2 One open water swim coaching sessions during April to September. One loop is approximately 500m around the edge. This lake is stream feed and is clean to swim in.

Please note there are no changing facilities at this lake

Venue 3

Stubbers Adventure Centre
Ockendon Road
RM14 2TY

Fee for coaching is £55 plus an additional cost for me to use the Stubbers Lake.

Overcome your fears with Mark who’s been swimming in open water for more than 30 years and avoid the mistakes made by inexperienced open water swimmers with Mark’s help, advice and swimming coaching. Contact me now to discuss or arrange your open water swimming coaching & training!

Swim Coaching Testimonials

“If you want the best trainer, Mark is your man. He helped my children aged 7 & 8 to swim in open water and gave them excellent transition and dietary advice too. He put us all at ease, focused on the children and worked with their strengths and improve their technique. He encouraged them and gave them the “can do it, will do it” mind-set. Mark is a great inspiration and very patient especially when you have a cheeky daughter.”  PJ (40 & Mum of 2 kids)

“Mark is supportive, enthusiastic and knowledgeable, and he is happy to show even the greenest newbies how to get into the water and swim with confidence. I can’t wait till the new open water swimming season starts!” Cheryl Boston

“Without Marks patience confidence and help I would never have even be able to start my first open water swim triathlon.” Anna S (50)

“I am a seasoned runner and triathlete of over 35 years’ experience. I have completed sprint , Olympic and Ironman distances, and always found the one discipline I tended to shy away from was swimming , especially if it was open water so I enlisted Mark Kleanthous who is a legend in the Triathlon world, notching up an incredible 38 Ironman finishes. I told Mark and said I was a bit nervous of the swim as it was open water as I’d had a few bad experiences with panic breathing in the water. He said he would give me a few lessons and look at my technique and give some advice on how I can overcome my fears and swim strongly and efficiently. During my One2One coaching session with Mark he was very complementary of my technique and gave me a few really helpful tips for starting / during the swim and exiting the water and getting out of that figure gripping wetsuit. The result on the day was my best ever time for an Olympic distance open water swim (31 mins), and I was 3rd o/55 in the race. Thanks Mark you are a legend thanks for the advice! Mervyn Phillips (58)

“Thanks to you Mark I can now swim front crawl every time I now open water swim thanks to you. You put me at ease from the moment I met you showed me how to correctly put on my wetsuit get into the water learn to relax and swim effortlessly.” Martin Lewis (53)

“You were my last chance to overcome my fears I have seen several other swim coaches but still could not overcome my fear of open water. Thanks for helping me overcome my fears, I can happily report since our coaching sessions I have not had one panic attack. You don’t know how grateful I am of you helping me achieve my ambition of competing in open water swimming events and triathlons without the fear I used to experience.” SW divorced Mum of 4 teenage kids

“Mark helped me (44 year old plodding house wife) greatly to improve my swim technique in open water. Gave me the confidence to go for it. Definitely would call upon him again.” Palwinder Jeffer (44)

“Every time I got into open water even with a wetsuit on i thought i was going to drown! That was until i had an open water swimming coaching session with Mark. Your professional but calm coaching showed me how to get into the water and relax my breathing, this has made all the difference. I actually went swimming in the sea holiday without a wetsuit for the first time EVER because of your help. I will be forever indebted to your time and effort you gave me.” Alice Woodward (61)

“It was the best investment in time I have made. I had plateaued for years and simply could not improve my swimming. In just one hour with you I learnt lots which I will use in the future. Thanks again.” Shelly Anderson (26)

“I never thought I would learn so much and improve so quickly in just 2 open water swimming sessions with you. I wish I had used you 2 years ago. I easily managed to complete my 1 mile open water swim and you will be proud to know my partner who was watching me from the bank said I even swam in a straight line! Thank you so much I will use the knowledge and technique you gave me for the rest of my events this season. I will not hesitate to refer others to you and be in touch again when I plan on swimming longer open water swimming events.” Adam Coates (33)

“I booked in with Mark in the summer of 2015, meeting Mark I found him passionate and a great teacher. He helped me to improve my confidence in the water, gave good advice about my swim technique and explained to me how to aim for a specific landmark to improve the straightness of my swim. In the weeks after my session Mark was quick to come over and give advice when he saw me training and at events to give the extra encouragement I needed. I especially remember the BoxEnd Triathlon on the running course, he gave me the energy to finish the run when I felt dead in the water. Using Marks advice throughout the season helped to improve not just my swim times but my overall Tri performance. Although injured for 2016, I will be using Mark again in the future to help with my ambitions to complete my first ironman'” Edward Snook

“Mark is so much more than just a coach. I thought I could swim, he taught me to swim properly. Mark’s sessions and ongoing unconditional support has given me the confidence to take on new challenges and push myself to new levels. On top of that, he’s simply a great guy that wants all of his trainees to do the best they can. Highly recommended. Marks out of 10? At least 20.” David Foster (48) now Padstow Rock 1 mile open water swimmer!

“Mark help me reduce my mile swim time from 36 minutes to under 30 minutes since he has been coaching me. I knew I had the fitness with Mark’s help I was able to swim so much faster. Gavin is training for the English Channel with Mark’s training plans mentoring nutrition advice and coaching sessions.” Gavin Lewis (28)

“Mark guided me through my first open water swim. Although a confident pool swimmer I’d never swam in open water in a wet suit and found the experience easier to master with Mark’s close supervision. We went through everything from putting on a wetsuit without ripping it to drafting techniques. It was a really helpful session to set me on my way for my first Tri season & 14:47 for Ironman Nice France at the end of my first triathlon season” Nabil Lodey (43) London

“Thank you Mark I can now use my fitness from cycling and running and swim properly with no breathing difficulties since my open water swimming session with you.”  Nicholas Ashworth (52)

“I entered Ironman Wales with a couple of open water swim events behind me. I was extremely concerned having read how brutal the swim course could be and knowing that this was my weakest discipline, I looked for help. Mark was easy to find and coached locally. Mark was excellent from the first session he took it back to basics, made me feel extremely comfortable and at ease. Marks enthusiasm and knowledge proved invaluable. I used to literally swim in a large circle Mark helped me swim in a straight line. The swimming became enjoyable and I completed the swim course, which as usual for Wales in very tricky conditions but managed a PB. The swim had actually become one of my stronger legs. Thank you Mark you’re coaching and approach and the self-belief you gave me definitely got me across the finish line, Cheers” Glen Tritton (41) Ironman Finisher with limited triathlon experience Ironman Tenby Wales Swim 1:27 Bike 8:02 Run 4:45 total finishing time 14:42:01

“I am amazed at how much I progress forward without much effort after just 15 minutes of open water swim coaching with you. I feel far more confident & now swim faster for the same effort. I actually enjoy swimming now so cannot thank you enough. I am now considering an Ironman.” Hayley C (28)

“I came to Mark to help me to prepare for the London Triathlon having no experience in open water swimming and having only recently started swimming again. Mark helped me both acclimatise to the open water and develop my swimming technique and confidence. His expert coaching and positivity helped spur me on to feel successful at the end of every session and ultimately to enjoy and race competitively in open water triathlons.” Sam Huggil (32)

“Marks enthusiasm and belief in what you can achieve in the water inspires you to really go for it. Technically he is simply superb.” Jeanette Ager Music Teacher

“Mark gave me the confidence and skills I needed to venture into open water swimming as a complete beginner and then go on to successfully compete in several open water swimming events, he focused on quality coaching.” Alan Hay (55)
Alan is now an open water swimmer who has since entered 5k Windermere and a 10km open water swim.