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Swimming through the depths of a natural underwater museum, Roger Edmunds, Chartered MCSI, is privileged to see a part of the planet few have seen in real life. His hobby of closed circuit rebreather (CCR) diving has taken him to deep trenches and open seas around the world to explore WWII wrecks of aircraft, merchant ships and warships, and brought him up close to an amazing array of sea life, including dolphins, barracuda and octopuses.
This exotic pastime is far removed from his role as freelance finance director of his own firm of chartered accountants, which acts for regulated financial small and medium-sized enterprises (SMEs), mainly in the City. CCR diving allows Roger to escape to another world and “access wrecks that are often pristine or rarely visited”, in relative silence compared to an open circuit unit.
Longer, deeper divesRoger explains that CCR diving recirculates the gases used. Carbon dioxide is scrubbed and oxygen added to top up the amount of oxygen used. No gas is expelled, unlike in open circuit diving, which means the silence allows the diver to hear what is going on in the ocean, and not disturb the sea life.
“It allows for longer and deeper dives and an improved ability to photograph animals who would otherwise flee the noise of an open circuit diving unit,” says Roger.
Roger’s love of rebreather diving began in September 2009: “I borrowed a rebreather off an instructor on a Red Sea dive while on a wreck diving holiday. I found it quite different from the open circuit experience. My dive on this occasion was to a depth of about 15 metres, followed by another at about 37 metres. This sold me on the system. Learning the technology, computer systems and attending the training courses took roughly three years.”
Roger was 66 when he completed his first course in 2012 in Lanzarote, renting his equipment to see how well it dived – a good tip, as buying a unit and discovering that it does not suit you can be an expensive mistake.
While “Chepstow, Vobster in Somerset and Stoney Cove in Leicestershire are the closest deep water quarries used for training,” Roger prefers “warmer, open water for training, such as Malta, the Red Sea or the Caribbean”.
His favourite diving spots are the “Cayman Islands for critters and Chuuk Lagoon for wrecks. The Cayman Trench is deep, which attracts the Pelagic species, including tuna, sharks and large rays. Chuuk has over 70 WWII wrecks of aircraft, merchant ships and warships at all depths, including many around 70 metres.”
"Chuuk is an underwater museum with a no-take policy, except for photographs"
Safety is paramount and Roger services, rebuilds and tests his rebreather unit each season, working through from pool testing to quarry dives, shallow open water English Channel dives and deeper diving.
The deepest dive Roger has done is to 71 metres off Malin Head, and the longest amount of time he has dived for is two hours and 31 minutes, exploring the Japanese Kamikaze-Class destroyer Oite inside the north pass to Chuuk Lagoon. “She was blown into two by Avenger aircraft from the US Fleet during Operation Hailstorm. Chuuk is an underwater museum with a no-take policy, except for photographs.”
The risks of deep sea diving include decompression illness, disorientation, hypothermia, oxygen toxicity and equipment failure. “On the HIJMS Oite the silt got stirred up, reducing the visibility in the semi-darkness to nil while I was inside the bow section,” Roger says. “I could not see the way out. The few minutes for it to settle seemed a long time. At that depth every minute adds more than a minute of decompression time!”
To those who might be interested in taking up Roger’s hobby, he has this advice: “You need to have good attention to detail, an awareness of your surroundings and preferably be immune to seasickness."
This article was originally published in the Q3 2017 print edition of The Review. The print edition is available to all members who opt in to receive it, except student members. All eligible members who would like to receive future editions in the post should log in to MyCISI, click on My Account/Communications and set their preference to 'Yes'.