The Pelagian Way

gbmay

The Pelagian way
I have been an Inspiration user for the past five years and have enjoyed over 250 dives on my “Hammer Classic”. I felt that switching from an ECCR to a DCCR would be a piece of cake; boy was I wrong! There is a whole new technique you need to learn if you are going from ECCR to DCCR.

My journey started this past Friday when Andy Fritz, genius behind the Pelagian, arrived in Anilao, Philippines to train Matt, my partner, and I on the unit. At first, I was not very happy that I had to go through a five day program, to be certified on the unit, as I had many hours of experience on the Inspiration; but as the days went by I fully understood Andy’s insistence that the course had to be five days.

Our training began with a thorough understanding on how to assemble the unit. The Pelagian is delivered as a kit so there are a few things you need to put together, nothing difficult and anyone can do it quickly even if you are mechanically challenged. Once we assembled our units we went through a very thorough checklist. Andy was very insistent on a three-point calibration routine. At first it seemed like a royal pain in the ass but as he explained the rationale behind the three-point calibration it started to make sense. First, you calibrate the unit at (20.9), second you calibrate on 100% O2, flush the loop three times, similar routine all CCR’s use but the third point is the one that I believe can really save LIVES! The third validation point (1.6) is performed at 6M to check the ability of the cell to work under stress. If the cells pass all three tests then you are fairly assured that you are good to go.

The Pelagian performs like a fine-tuned sports car. The counter lungs are tailored to your body, even a slightly overweight person, like me, can appreciate the way the lungs follow the contour of your chest and help achieve incredible trim. You control PO2 through an adjustable needle valve coupled with short bursts from your O2 “add button”. At first, you have to work on it, specially coming from an ECCR, but at the end I believe it is safer for you to control your PO2 than to leave it to some electrical mechanical device. The Pelagian has two 02 cells that are monitored by a neat and small LCD device. The P02 meter shows you three decimal places, unlike most PO2 meters that only show you two. Andy has further refined the position of the cells so that you can easily validate the cells by exhaling, triggering the ADV device and then quickly verifying the output of the O2 cells. So, if you are at 20M, with an air diluent tank your PO2 should read (.21X3). Also, by “blowing diluent” through the cells it helps keep them dry. After a number of dives I barely had a moisture on the cells.

So let’s go diving… My first dive was down to 12M to become acquainted with the unit. We performed a number of drills, shutdowns, purge the loop, set low/high set points etc… I found the unit to be extremely responsive and by the end of the first dive I was able to maintain decent trim and enjoy the great effortless breathing (WOB) that the unit provides along with a great DSV and BOV combined. The second and subsequent dives where more drills and learning how to use the needle valve and O2 injector button. If you are new to DCCR’s you need to work on this as the tendency is to ONLY use the needle to add O2 when you need to use both the needle and the injector button. While it may sound complicated, it really becomes second nature after two to three dives. As the week progressed, I found myself enjoying the unit even more. I was able to hover at 3M with no problem and maintain a reasonable PO2 throughout the dive. Our last dive was down to 40M and that is where the unit begins to shine. As you go deeper, it becomes easier to maintain PO2 and the excellent trim of the unit makes it effortless to dive. There is absolutely no drag on this unit; it feels like the unit becomes part of your body. My ECCR feels like I have a truck strapped to my back. I have not tried the Pelagian on a strong current but I am sure that the excellent trim of the unit will make it easy to maneuver.

Taking it apart for cleaning and disinfecting is also very simple. The hoses and counterlongs come off very easy and are easy to clean. Andy, really put a lot of thought into taking this unit apart for traveling. The unit less tanks weighs in at 11K. You can put the whole unit, less tanks, in a backpack and take it on board. Try doing that with a Meg or Inspiration.

I believe Andy has done an incredible job of building a simple yet sophisticated piece of gear that I would not hesitate to take down to 100M+ once I have enough time on the unit.

George

Drmike

What does DCCR stand for?

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kieranu

I believe it stands for diver-controlled CCR (its actually DCCCR) though beats the sh1t out of me what the difference between that and mCCR apart from as a marketing-term is.

silent running

Thanks for the report George, always interesting to hear a first hand account of training on a new unit. I continue to be impressed with the Pelagian and hope to give one a spin sometime. -Andy

silent running

I think it's a reference to the use of the needle valve as means of O2 delivery-diver has full control over the flow at all times. Which I guess means that Mike's Rat is also a DCCR...

Drmike

I think we have quite enough of those thank you very much

mCCR then.

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wearypanda

George, Thanks for the great write-up of your Pelagian training. Have some greens .

I trained with Andy earlier in the year in Koh Samui and I agree with all you say about the Pelagian and Andy's thorough approach to training. I certainly like your description of the Pelagian as the 'sports car' of rebreathers. The Pelagian is extremely well engineered and there are just so many details in the unit which are the result of lots of experience and some very clever thinking by Andy.

I am taking my Pelagian out to the Red Sea in October and cannot wait to get back into the water with it.

Happy and safe diving.

Andrew

Steve

I would have thought the view that 2 sensors was rendered to the world of putting butter on burns.

Can someone explain to me how one can validate sensors if there are only 2? As I see it a dil flush drops the pO2 sure but with only 2 sensors you can't tell if the bung sensor has failed high or low. Bailout is the only prudent option. There are unfortunately enough dead people to bang this point home to us.

Assuming that bailout is the trained drill then why mention sensor validation at all?

What is the go?

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Rebreatherlab

Diver Controlled Closed Circuit Rebreather. Actually I just needed some cool abriviatition to balance the Pelagian logo and was always fond of the Soviet's CCCCP or whatever it was.

Cheers,

Andy

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wedivebc

A dill flush validates the sensor against a known quantity as opposed to voting logic that validates a sensor against (hopefully) known good sensors. In fact Andy's philosophy is quite sound. Use a very small amount of dil to validate and you can check them as often as you feel nessasary.
I dove my converted dolphin for quite a while with 2 sensors and never felt safety was compromised. When one sensor tests bad you return home on the sensor that passes the dil flush test.

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Dave....

Man is the only animal burdened with the knowledge he will eventually die