My view on the Pelagian DCCCR

rogeringebo

As previously discussed on the forum there is now a brand new fullyclosed rebreather on the market. I was in the first user course ever and it was held in Thailand with Big Blue Tech under PSA standards. Here comes a small review:

If You want to read up on the Pelagian DCCCR you can do that on www.rebreatherlab.com.

My first impression of the machine was that I was incredible small and light. My Classic KISS felt rather huge in comparison. The unit was equipped 2,7 litres alutanks valves facing up. I dived with an alublackplate, Agir 50 wing and 3 mm full wetsuit. One of the first things I realized under water was the fantastic balance, no sign of any “seahorse style diving”. All the weight was in the upper part of the machine and all air in the scrubber head and hoses were kept to a minimum to prevent the typical heavy rear of a rebreather. With this rebreather I could have the perfect trim like when I dive on an open circuit. One of the really strong points is that the distance between your back and the very back of the rebreather/scrubber is kept to a minimum which means that the balance is kept very close to where your own would be. If I lean over just a little bit on the side with the KISS it wants to turn me over because of the distance created by backplate/wing/alubox with counterlungs and finally scrubber. All this means that the balance is quite far from where your own would be. The counterlungs are over the shoulder-style like on the MEG but are curved under your arms next to your ribs following where your own lungs would be, creating a very ease of breathing. I was not to thrilled to start of with because I like having my counterlungs on the KISS protected by their casing and because I always dive with slingtanks thought the CLs would be squeezed behind the tanks and be interrupted when you breathe but the solution for that was special D-rings that comes out a few centimetres sideways so that the lung can move freely. It worked perfect. I think the MEG has a similar solution. By the way, I used my own backplate and harness. I would have preferred larger lungs but that you can order what size you want. The lungs felt solid and are made by the same material as innertubing for tires rapt in cordura so you could penetration dives without worrying too much. The breathing-hose was very short and was a bit tricky to get over my head when gearing up because it is attached with T-pieces on the shoulders to the CL:s but worked great under water because no hose-weights were needed and the hose was not floating around pulling on the mouth-piece.

I really liked having the valves facing up, felt more natural to use them that way. It also makes it possible to use whatever tanks you like all the way up to 12 litres if that is what you prefer. Rebreatherlab has chosen to use regular canbands to don the tanks and scrubber which means it is very easy to take the rebreather apart when you come home. I use so called G-snaps on my KISS but they move around holding tanks even further away from where your natural balance is and make the Rebreather even heavier around the rear.

The machine was not equipped with DSV or ADV which I really liked because my DSV hisses and leaks when I use it to add diluent and my ADV does not give enough gas or fills the loop when I don´t want it to and interferes with the mix. On the Pelagian you add diluent by a simple push of a button like a BCD inflator and the gas comes at once, no hard moments during descents when your CL:s compress and you have to inhale like crazy to make the ADV kick in, which creates a lot of build up of CO2.

You bailout to a Scubapro air 2 that are attached to your wing, close at hand before you go over to your real bailoutsupply.

The big news for me was the way you add O2. The Pelagian works very much like the KISS but you can change the flow as you dive with a needlevalve from Swagelok. I found that to be very useful because I tend to use very different amounts of O2 depending on the dive and I don´t want to change the IP on my first stage all the time. The regulator is not blocked by a delrin-plug like on the KISS but change with the surrounding pressure. To start off with I thought I would have to screw on the needle all the time but it turned out to be very easy. A typical dive looked like this:

Ok, I know I want to dive to 40 m. I fullyclose the needle for reference and open maybe half a turn because at that dept I will be helped quite a lot by the surrounding pressure. At 40 m I boost the PO2 with the manual button to, let´s say 1.2, start swimming and observe what happens on my gages, it is likely that the PO2 will drop a little bit too quick and I open the needle a little bit and by then I usually find around 1.2. This procedure becomes second-nature after a few dives and one find it much quicker and learn how much is needed at each depth. This is a big help on the last decostops when we all know how hard it can be to keep up a high PO2. It makes quite a difference if you have, let´s say, 45 minutes to do on the 6 metre stop.

The unit has 3 sensors and 2 of them supply the 2 displays and the third is connected to let´s say, a VR3 dive computer. You can order it with 3 display like the KISS but I have rigged my KISS the same way so I was happy with the setup.
Another nice feature is tha you can easy validate your sensors by blowing diluent straight over the sensors faces and you don’t have to purge the whole loop to do this,just gently press the DIL add button.

Because I have dived a manually controlled rebreather before all of this came very easy to me but its very important to monitor the po2 very closely,but that one should always do anyway.
Personally I found the Pelagian to outperform my beloved Classic KISS and that stung a bit of course.

The price was certainly appealing aswell,4400 USD compared to Jetsams 5300 for the KISS (think that is accurate)

One could really tell that the guy that designed the Pelagian has a lot of experience from Rebreather diving and have addressed the usual RB problems..weird balance,size,weight,complicated maintainance work between dives and so on.
He showed me a photo of the Pelagian next to a Sport KISS and the Pelagian was considerable smaller…
I came home to Sweden from Thailand yesterday after dragging a ton of divegear across the world and the small size and low weight of the Pelagian would have made my trip a lot easier
My girlfriend and I probably had the heaviest carryon ever known to man but that is another story.

Everything above are just my own opinions and views and might not suit other divers but I hope you have enjoyed my review.

Cheers Rodge
PSA Pelagian diver #1

silent running

Hello Roger, thanks for the detailed post. The Pelagian is looking like a serious contender. But I have some concerns:
-The scrubber design, what type is it, whats the flow pattern and how much testing has been done and by whom? This is one of the hardest and most expensive things to get right in Rebreather design. And how does the WOB compare to other OTS CL units?
-How does one reach the top mounted tank valves? I would not want to dive a unit whose valves I couldn't turn off/on while using it for obvious reasons.
-I like the simple/minimal 2 sensor concept with a place for a 3rd compu integ. But I don't like those Jetsam/Explorer type pressure fitting/O ring displays. They are not as foolproof as potted displays and are prone to flooding. If we are going with the simple KISS type valve and the design is supposed to be simple, why use a powered display at all? Why not go with high output sensors and a passive needle display for a secondary, like the Prism/MKs?

The adjustable KISS valve, OTS CLs, easy dil flush sensor layout, double bag CLs are all excellent features, so it's off to a great start. Let me know what you think about the concerns I voiced above. I have been waiting for a passive CCR I could whole heartedly recomend. Thanks-Andy

rogeringebo

Hallo!
The scrubber has an axial flow design and so far has been tested by the designer of Rebreatherlab and not by any test agency and there are no test results but the scrubber is very simular to the CK.
Reaching behind your head for the tankvalves are very easy,they are located even closer to your shoulders than your average twinset because the tanks are smaller. Ican post some photos from the course if someone just explain how its done.(Im a diver,not a computer wiz=)
The cable glands on the Pelagian that comes out on the market might be Swagelok or simular. There will be cables between head and displayhousing and not pipes that could leak and flood head and housing.
I dont think there has been any tests between the Pelagians CLs and other brands but I was pleased with how they performed.
Ok,lets give the photos a chance.........

/Rodge

Attached Images

	Andy Pelagian pose.jpg (6.1 KB, 528 views)
	Hanging.jpg (6.1 KB, 518 views)
	Pelagian at work.jpg (5.4 KB, 514 views)
	Valvedrill.jpg (8.0 KB, 518 views)
	Pelagian vs SportKiss.jpg (8.5 KB, 522 views)

schford

Great Post!

Thanks.

Lou - one for the Articles Section I think!

Stuart

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caveseeker7

Exactly my thoughts, in both regards.

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Cheers
Stefan



"Political Correctness is a doctrine, fostered by a delusional, illogical minority,
and rabidly promoted by an unscrupulous mainstream media,
which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.!"

jont

Sounds like they have some good ideas backed by sound thinking, has anyone else been on one??

Philippe GERIN

Hi Rodge,
Interesting article, thank you.
How'bout a tear-down article and pics?
Questions: did you dive it with a drysuit yet? How are the CL's with it + inflation button/valve. Reaching valves?
I noticed the pic next to the SK is the "shorter" scrubber. Would there be a pic with the "Explorer" scrubber next to a CK?
I take it the all lot is assembled over a kind of back-plate with cambands that you bolt to your own BP? Do you need the 2 plates or can juts use your plate if you have, say, the Portland plate with slots for 2 sets of cambands? How is the DSV manipulation? Bloody hard as on a Dolphin or as easy as on an Azimuth?
Best
Philippe

rogeringebo

Hi Philippe!
Sorry,dont have any teardown photos but Im sure they will update their website soon..
The explorer scrubber looks the same,only a few centimeter longer and holds 3.5kg instead of 2.7kg (I think thats the right numbers)
I am not familar with the backplate you are refering to but the one that comes with the machine is made of thin but very stable staniless steel and have bolts on it that hold your wing and backplate with wingnuts.It is made to hold everything in place but the head of the Rebreather is not attached like on the KISS,Head and scrubber comes off together when you losen the camband so its very easy to separate everything when you want to clean it.The scrubber material is squized together by springs btw...
The mouthpiece I used was a simple ballvalve construction without any o-rings and performed really well...everything was really tight....when performing negative test,one could leave the unit for an hour and it did not loose one bit of vacuum.Turning the valve was not hard or easy,gave that feeling you get when you close the door of an Mercedes..you could feel it was of good quality..
I know that there are other mouthpieces/DSVs planned so we have to wait and see.
I have not tried the unit with a dry suit but I dont think it will cause any problems,maybe a little hard to turn the needle valve with drygloves but I have adressed the designer and Im sure they work something out.
Cheers Rodge

silent running

Hello Roge, thanks for the answers. Now more ?s:
-What kind of duration were you getting for your axial scrubber in that warm Thai water, with what size mesh/brand?
-Do you know why he went with an axial design, was he trying to keep the unit smaller?
-Have you dived other OTS CL units and if so, how did the Pelagian's WOB compare?
-Guess I'll have to take your word on the ease of reaching the tank valves. I've never had good luck with that move on an Rebreather.
-As for the displays, I was also concerned about the face of the displays which seem to have the same screw down user servicable 1 ata pressure fitting as the KISS displays. I assume this is where the batteries are. Is this true? Every KISS user I've met has flooded their displays do to over or under tightening the screws. Did you have any problems with changing batteries or displays flooding or cal screw problems? Not a fan of this design. I don't like unpotted electronics in water. It would be nice if somebody other than SMI and the MKs had a passive, high output, sensor driven needle display. That would really be Keeping It Simple. How nice it would be not to ever have to change/buy/bring batteries again, except the 1 in your computer....
-Is there a way to drain the lungs underwater?
I know you're not the manufacturer so thanks for taking the time to give your impressions and answer ?s.-Andy

rogeringebo

Hi Andy!
The battery is a regular 9volt and are located in the head of the scrubber in its own o-ring sealed casing and should last for a very long time....quality of the batterys we used i Thailand varied alot but with a proper battery one should get 3 months of use.The magnet turning on the displayhousing have 2 different settings,slide it half way and the display turns on,slide it all the way and the backlighting turns on,saves a lot of battery as you can decide during the dive if you need the backlighting or not...calibrating the displays/sensors are very easy and not so difficult as on the KISS which can be SO sensetive....this one changes less when turning the screw..
During the dives outside the course I did 6 hours on a scrubber filled with Drägersorb and the designer dives at least 6 hours all the time,he told me that he chased a whaleshark for 20min after being past 6 hours,when he came up the mashine was steaming with moist but no signs of headache....maybe not scientific proof but gives a idea of what one can expect...
He is working on the displaycasing and are thinking about potting it,cast all in one piece,we will se what the future holds.
Yes you can drain the lungs,they have the same type of dumpvalves as a normal BCD but with a modified spring system.
Give me your e-mail adress and Ill send you a bigger photo of how easy it is to reach the tankvalves.....

Cheers Rodge