5/15/2009 12:52:00 PM Hitting new depths in the name of science Divers venture 200ft below the waves to research Bermuda’s coral reefs
Deep breaths: Technical diver Corey Eddy had three air tanks plus an emergency bottle. *Photos by James Whittaker
Water sight: Graham Maddocks, who runs Triangle Diving, ascends to the surface after a deep-dive. He claims one of the toughest things is dealing with the heady effects of narcosis.
Corey Eddy took a deep gulp of compressed air from the twin steel tanks strapped to his back and glanced at his dive watch.
Despite the ringing in his ears and throbbing in his head, he could see the depth column clearly - 193ft, the deepest he had ever been.
The effect of nitrogen narcosis - sometimes called the rapture of the deep - was kicking in and simple tasks at the surface were requiring the concentration of a Buddhist monk.
But Mr. Eddy - part of a team of technical divers collecting coral samples - has endured intense training to handle conditions like these.
Narcosis
In the deep ocean there is no escape from narcosis - a dizzying, almost narcotic high that enraptures divers below 100ft.
Even advanced divers rarely venture below 130ft, and with good reason.
"Operating with narcosis is almost like asking someone to drink a bottle of Jack Daniels and then walk in a straight line," said Graham Maddocks, part of the dive team from the Bermuda Institute of Ocean Sciences (BIOS) and his own firm, Triangle Diving.
"You can't avoid it, you simply have to understand it and learn to cope."
The research the dive team is conducting was supposed to be carried out by a submarine. But developments in local dive training led to the establishment of Triangle's tech team.
A link-up has enabled BIOS researchers like Mr. Eddy to plumb new depths in the name of research.
The team is collecting coral from the deep ocean to compare its DNA to specimens found in shallower waters.
They hope to discover if the reefs - comparable to rainforests in their biological diversity and value to the environment - will replenish themselves in the event of an ecological disaster.
A host of scientists are involved in the analysis but the hazardous task of collecting samples was down to the four divers, who ventured into the deep last week.
Narcosis is not in itself a killer. There is a fine line between the feeling of well-being it creates and descending into a state of high anxiety.
Mr. Eddy said: "I've read stories of guys who have dropped dive knives and freaked out over it, getting anxious, over-breathing and losing control.
"Part of our training is to recognize that at those depths funny things may happen and not to let them bother you or snowball into a worse situation."
An anecdote about a diver who offered his regulator to a fish served as a cautionary tale to the team as they prepared for the mission. But mistakes would not have to be as dramatic as that.
Miscalculating the depth, the air left in your tank or the time permitted at that depth could be equally threatening.
Past 220ft, oxygen becomes dangerously toxic and it is not unknown for divers - perhaps lulled into a false sense of security by narcosis - to accidentally stray into that lower strata, pass out and drown.
The other major fear for any diver is the Bends - a crippling, often fatal illness caused by the release of nitrogen bubbles into the bloodstream on a too-rapid ascent to the surface.
Oxygen
The digits on Mr. Eddy's watch and written in marker pen on a dive slate dictated the terms and conditions of the dive.
Crunching the numbers, the 20 minutes he has spent in the 190ft range meant he would need an hour to ascend to the surface.
So far everything was going to plan. The hardware strapped to his body - twin steel tanks of compressed air, an additional 'pony' bottle of air and a tank of pure oxygen - would ensure he could get to the surface without running out of gas.
The coral had been collected - an arduous task of battling the mental fog to chisel at the reef - and sent to the surface via an inflatable lift bag.
Now there was just the boredom of hanging on a rope for an hour to contend with. The work of Mr. Eddy and his team - Alex Chequer, the dive safety officer at BIOS, Graham Maddocks and Graham Christmas - is part of a combined research project between BIOS and the University of Miami's Rosentiel School of Marine and Atmospheric Science.
The research, funded by the Department of Environmental Protection and led by Dr Ross Jones, head of the Marine Environmental Program (MEP) at BIOS, will paint a picture of how strong Bermuda's reefs are.
It will also determine how capable they are of resisting the effects of human disturbances.
The theory is that deep areas may act as a refuge and allow corals to live in relative safety away from the effects of humans. Dr Jones said: "If there was a bleaching event in the shallow water reefs - caused by unusually high temperatures - a disease outbreak or damage to the reef from an oil spill, from sediment re-suspended by cruise ships or even from a ship grounding, would the reefs make a comeback?
Resilient
"We're examining the genetic relationship between the deep coral, which is relatively safe from those kinds of human factors, and the shallow coral which is most at risk.
"We should find out if nature has a back-up plan for Bermuda that will allow it to be resilient to change."
It's an incredibly specialized research project and Mr. Eddy admits combining the diving and science requires a combination of geekiness and 'Type A' extremism. But he insists the risks are worth taking.
He said: "With the right training, preparation, experience and control, it can be done well."
Mr. Maddocks revealed the link-up with BIOS on this project is one of the first major assignments for Triangle's new tech team.
The firm branched out in the winter, running courses to train divers in more complex deep-diving. He hopes the link-up will lead to more projects providing assistance to scientists.
Mr. Maddocks said: "Looking for new challenges and experiences is the only way to live and if we can help with worthy projects then even better."
Posted: Monday, May 18, 2009
Comment by:
Paul Larrett
I have yet to hear a cogent argument explaining the logic behind deep air. Luckily, accidents that would reveal the critical and most acute problems associated with “deep air” diving are rare and so “deep air” proponents usually “get away with it”. That does not mean that we should do it though, as every diver should seek to optimise their (and their teams’) safety and enjoyment. Regulator failures are rare, but that does not mean that we should not service them and look after them.
It is because serious incidents are relatively rare that inexperienced divers are blissfully unaware of the pitfalls of “deep air”.
“Coping” with a bit of narcosis when things are going well is one thing, breathing dense air when one is having to work hard in an emergency situation is another. The elevated carbon dioxide levels (hypercapnia) just compound the narcosis and increase the chance of oxygen toxicity just at a time when the diver should be at their sharpest. Perceptual narrowing causes bad decisions to me made and the diver is physiologically impaired such that they are unable to perform at their best.
Now that trimix training is readily available and relatively widespread overseas, there is no excuse to compromise safety by using “deep air”. Trimix diving involves using a breathing mix of helium, oxygen and nitrogen. By reducing the proportion of nitrogen one is able to eliminate narcosis. By reducing the proportion of oxygen one is able to eliminate oxygen toxicity. Adding in the inert gas helium reduces the density of the gas making it much easier to breathe. Trimix is thus a much safer alternative but one which some recklessly and stubbornly choose to ignore due to its increased cost.
A professional organisation such as BIOS should not be sacrificing safety for the sake of the extra cost of helium. If they intend to put themselves forward as a serious scientific enterprise, then they should adopt best practices, ones that use science to reduce risk and enhance results and enjoyment.
