November 2, 2008

Rebreathers!

     The most exciting opportunity to arise at DEMA was an invitation for all three scholars to join a rebreather class being taught by Jeff Bozanic.  Jeff has an incredibly varied and interesting background in science and in diving, and a talk he gave at the LA County Natural History Museum that I attended while a junior at USC was a major factor in inspiring me to take up diving.  Jeff has been a strong supporter of the scholarship for a very long time, and quite a few former scholars have said that this course was the highlight of their scholarship year.
Jeff
     Jeff's courses are also known for their intensity and thoroughness.  With less than a day to recover from DEMA madness, Magne (one of Jeff's students from Norway), Steve, Eline and I arrived at Jeff's house excited and a little nervous to begin what would be the most challenging week of diving any of us had ever gone through.  After picking up the units we would be using from the course from Richard Graff of Xtreme Scuba, the first few days were focused completely on lectures regarding the history, physics, physiology, design and practice of diving rebreathers.
The three scholars hard at work
     All of us would be learning to use an Evolution, Inspiration Classic and an Inspiration Vision, all three of which are electronically controlled close circuit rebreathers (eCCRs).  This means that they have a fully closed breathing loop, complete with a suite of sensors that monitor the oxygen levels inside the loop.  If the controller detects low levels of oxygen within the loop, a solenoid will fire, injecting oxygen into the loop.  This type of rebreather is usually flown 'fully automatic' meaning that the diver allows the computer to control the partial pressure of oxygen.  However, we would be learning to fly the rebreathers completely manually, using the electronics purely as a backup.  If any of that is unclear, and you want a little help understanding it, read this.  If you really want to know how a rebreather works, you should read Jeff's book, Mastering Rebreathers.  If you are at all interested in diving technology or rebreathers it's a must-read.  If you can't be bothered to read either, know that a rebreather differs from SCUBA in that it recycles the air the diver breathes by removing CO2 via a chemical 'scrubber' and periodically replacing the oxygen that the diver metabolizes.  When used properly it can offer vast benefits in decompression obligation and gas consumption.  In technical diving rebreathers can sometimes be used to complete dives that would be impossible on open circuit due to gas consumption.
Cookie-check, Rolex-check, problem sets-check
     After completing the first few days of our training, we were really excited to be getting in the water and trying out our units.  On Thursday we met our assistant instructor, Ian Martin, and spent most of the day in Jeff's pool, working on emergency drills, managing our PO2 and our buoyancy.  On  Friday we headed down to San Pedro and boarded the Psalty V, captained by Gary Jackson and his dog, KO.  We were also joined by Jeff's friend and partner, Elaine Jobin, who was there to photograph the trip and join in on the fun.  Jeff, Ian, Magne, Eline, Steve, Gary, Elaine and I would spend the next three days on the Psalty V completing the class and diving all over Catalina.
Karl checking up on us
     Learning to dive rebreathers can be difficult and dangerous at best, especially when your students are a trio of young divers who have just enough experience under their belts that they're beginning to think they know what they're doing underwater, so Ian and Jeff approached every open water dive with extreme caution and careful planning.  Rebreather diving is very different than open circuit; it requires extreme focus and concentration at all times.  The dives were really exciting and fun, but very challenging.  Ian and Jeff didn't hesitate to throw every emergency or problem imaginable at us at any time, often several simultaneously.  On top of all of this we were expected to constantly monitor and maintain our set points without any assistance from our electronics.  It was frustrating at times, but Jeff and Ian are fantastic teachers, and by the last few dives of the course we were beginning to feel like real divers again.
Bailing out
     After the week was over, I definitely understood why so many scholars had spoken so glowingly about Jeff and his courses.  Jeff and his family were wonderful to us during our stay at his house.  They truly made us feel like members of the family.  Gary and KO were also terrific hosts, the food, diving and accommodations on the Psalty V were absolutely top-notch. One of the coolest parts of the week was going to spots I'd dove on dozens of times before and seeing them in a completely new light thanks to the lack of noisy bubbles from our rebreathers.  We also had a chance to see some old friends on the island including T-bird and Karl and check out the Two Harbors' haunted house!  Best of all, each of us encountered and overcame some significant obstacles during our training, and I know that we all really improved as divers.  If anyone is feeling extra generous around Christmas-time, a rebreather is now definitely holding down the top spot on my list.

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