S5E17- Ashley Semmens: The Clearance Diver who is finning the English Channel

Ashley Semmens is a former Royal Australian Navy Clearance Diver who served for 18 years, specialising in explosive ordnance disposal. He has deployed multiple times, including to Afghanistan, and participated in Australia's military withdrawal in 2021. After surviving trauma from an IED attack, a sniper incident, and a horrific shark attack aftermath in Sydney Harbour, Ashley was medically discharged due to PTSD. Now, he's preparing to swim the English Channel — not just any swim, but on his back, using fins. It's a fundraising mission for the Navy Clearance Diver Trust and a deeply personal journey into fear, resilience, and purpose. In this episode, Ash opens up about overcoming fear of the water, losing close mates, post-service mental health, and how he’s turning pain into a platform for support and recovery. Key Moments 00:00 – Ben and Tim intro the episode and Ash’s unique goal: finning across the English Channel 01:14 – Comparison to Sam Penny’s Channel swim (Season 1, Episode 27) 01:40 – Ash’s clearance diving background and fear of water after trauma 02:45 – Military and Afghanistan service; PTSD and recovery journey 04:00 – Ash joins the conversation, starts with early life and growing up in Adelaide 06:00 – Competitive swimming as a teen; early struggles and successes 07:45 – 2003: Racing against Grant Hackett at Nationals 09:18 – Backstroke vs freestyle debate; Ash’s short course gold medal (with caveats) 10:00 – Natural transition to the Navy from competitive sport 11:01 – Joining as a direct entry diver and diver vs boatswain's mate decision 12:01 – Clearance Diver selection process explained — 10 days of being wet, sandy, and psychologically tested 14:07 – What Ash learned about focus, fatigue, and resilience during selection 15:00 – 2009 shark attack incident: Ash explains what happened to Paul de Gelder 17:34 – Ash’s role in the aftermath: trauma from cleaning the boat, psychological impact 18:29 – Lingering fear of large bodies of water, even lakes 20:00 – Later incident at Jervis Bay: panic before dive leads to difficult team moment 21:12 – Realisation of responsibility and shame around not seeking help 22:30 – Stigma and lack of psychological support during service 23:45 – What clearance divers do: diving, EOD, underwater repair, and land-based ops 25:16 – How Ash ended up doing EOD work in Afghanistan despite being too junior 27:22 – Becoming the most junior sailor to deploy for combat operations in Afghanistan 28:46 – Motivation to deploy: “It’s like a footballer wanting to play a grand final” 29:00 – Getting targeted by an IED during deployment 31:30 About the Bushmaster 34:42 Pressure builds up 39:30 PTSD, cracks, symptoms and care 44:00 ‘More to live for’ – side story 49:10 Medical discharge… and there are no protective factors in the military uniform 51:00 Role identity fusion 54:30 Finning the channel- breaking it down External Links Navy Clearance Diver Trust Paul de Gelder – Shark Attack Survivor & Advocate S1E27 – Sam Penny swims the English Channel Contact Us Email: debrief@unforgiving60.com Instagram & Twitter: @Unforgiving60 Music With thanks to: The Externals – available on Spotify

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S5E17- Ashley Semmens: The Clearance Diver who is finning the English Channel is an episode from The Unforgiving60 by Ben Pronk, DSC & Tim Curtis.

This episode is 68:48 long.

This episode was published on May 31, 2025.

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