Category — Equipment
Deep sinkhole photo shoot preparation Part I – Modifying a brand new Rebreather for cave diving means being drastic and chop chop your new baby.
Again I am working on a CCR cave diver training program. This time it is Paul Nicklen, a award winning National Geographic photographer who is renown for his Arctic wild life photography.
Paul contacted me to get trained to the CCR cave diver level in order to shoot a National Geographic assignment in a Central Yucatan sinkhole. Most sinkholes are openwater dives but due to depth, decomposing material at the bottom that can be stirred up easily and the potential rock overhead they should be treated as cave dives in particular when it comes to zero visibility related drills and skills.
When Paul arrived we took his brand spanking new AP Diving Evolution Rebreather out of the box and modified it for cave diving. The biggest challenge and changes are related to the fact that the cave cave diver needs to be horizontal in the water column and Rebreathers are notorious for not wanting to be horizontal in the water.
The first step was to transplant the units internals from the yellow box into a Tec frame tube allowing easy access and the attachment of larger 3 ltr steel tanks. A stainless steel back plate was added to streamline the original harness, centralize mass and move the unit higher up on Paul’s back while drilling new holes into the back plate.
A small weight was added high on top of the left diluent tank to further force Paul into the horizontal and counter balance the left hand side bailout tank.
Further modifications are the larger Inspiration scrubber canister prolonging bottom time from Evolution 2 hours to Inspiration 3 hours and turning the Evolution Plus into a Inspiration. A AP Diving BOV – Bail Out Valve was added to allow the diver to get off loop even under severe Hypercapnia conditions. Inline shut off valves where added to be able to isolate the ADV – Automatic Diluent Valve and BOV in order to isolate them quickly should a free flow or leak occur facilitating the internal and external boom scenario drills and skills.
The first day and a half where spend to assemble and modify the Rebreather into a kick ass cave diving machine. Putting the Rebreather onto Paul’s back, taking it off, modifying smaller or larger details, putting it back on.
Once we got to the water diving at Casa Cenote – Cenote Manati Paul had no trouble at all to get into the horizontal position by default. The time we spend modifying the unit was well worth the effort as the outcome of immediate horizontal comfortable trim was great to see and watch.
As we went through a refresher of Rebreather related emergency drills such as the Hyperoxic, Hypoxic, Hypercapnia, Boom scenario, partially and complete food recovery drills it became apparent how we transformed the basic Evolution Rebreather into a stable cave diving platform getting Paul ready to receive his Rebreather cave diver training program.
Stay tuned for Part II
May 21, 2012 1 Comment
Just before I went on vacation I taught a cave course with Mark from England who had recently moved to Playa del Carmen in his armoured car and Meril a French pilot extraordinaire. In the last days we also had the pleasure to be joined by Anneleen who had done her training a couple of months earlier and now came in to practice a little.
The first days we had Etienne with us who is assisting towards becoming a Cavern Instructor and Mauro who did his last assistance before his Intro to Cave Instructor evaluation which he passed later with flying colours … Congratulations again.
As always we started of with a bunch of training in the open water to get used to the equipment, the configuration and the local environment. Once they felt comfortable it was time to start with the cave related training which meant a bunch of zero visibility exercises first on land and then underwater to prepare them as good as possible for running through those exercises later in the cave.
Both of them did great and it was amazing to see their progress from day to day. It really always impresses me how steep the learning curve is in the first couple of days. I think the key to success is to introduce new skills and new information always step by step and let the student master the one before moving on to the next. I compare cave diving to a juggling act while riding a mono cycle. The main idea is first to learn how to juggle lets say two balls, then three, then more. After that learn how to drive a mono bicycle and then combine the two. Some people maybe will need first to learn how to juggle on a normal bike as a step in between and so forth.
In any case we had great fun and always a good spirit even if the days were long and the weather horrible.
At the end we did some really great dives and even as a team of three they rocked through multiple out of gas scenarios combined with zero visibility, restrictions and anything else a cave dive could possibly through at you!
After that I took some time off first to go exploring down in Tulum with Kim and after that was off to Austria to meet my baby nephew Lorenz for the first time. I spent three wonderful weeks with my family far away from the jungle and dark water filled holes. Of course being a true cave diving addict I had to at least spent an hour a day on you tube checking out some cave diving videos =)
Back in Mexico I started right off with Ivan who did his technical cave diver training with me some time back and this time came down for some multi staging and a basic DPV course. Since my schedule is still not that busy he decided also to always take some time off in between which worked great for me as it gives me the time to go down to Tulum and explore some more.
Since some time now I really have the great pleasure to be in a project with Kim a cave diving instructor who lives down in Tulum.
Kim found what he first thought was a virgin cenote in an area he was long interested in. Being super happy about the discovery he decided to call the cenote Lycka which is Swedish and means happiness. While freediving it he found that there was already a guide line in the entrance from a previous exploration team. He enquired with Jim Coke at the QRSS and no data was reported from any team about any cave in that area.
We then decided to make a joint effort of resurveying and retrieving the data and also while doing that, to look for further possible exploration. Now after we connected other Cenotes (one of them named Lorenz after my nephew) it already turned into Sistema Lycka =)
So far we make great progress and I am enjoying the time a lot. The cave is really very different with unique characteristics and colours. So I am sure not to get bored on my days off, thanks to Kim!!!
I make sure to keep you posted on the progress.
August 10, 2010 2 Comments