Maybe eCCR's really aren't the wave of the future for recreational divers?

silent running

Well Gill, I got over my worry about sharing cells btw the displays by using a system with high output cells which can drive my neat-o cool-o needle gage without any power. With the power to the elctronics off, there's no high current and the cells are totally isolated. I have reviewed the possible failure modes many times with different people and found that the possiblity of a high current leak from the electronics feeding back into the cells is next to nil. In fact it's never happened, not even when I flooded my battery compartment and sent god-knows-what kind of current through the battery pins. Nor to my knowledge, have any of the fully potted 2dry needle gages developed any leaks. This system has it's drawbacks, but reliability isn't one of them.

As for first hand experience, how about your first hand experience diving with that Prism guy who did 53+hrs in 11 days without even a minor problem?

Don't get me wrong, if you must have integrated deco, I think you're making a good choice going MCCR instead of that little big fat nanny evo. Any ECCR that won't allow you to fly the rig manually, without any power and/or a total electronics failure, is simply not suitable for diving in remote locations, period. Happily, my ECCR doesn't have this problem and has never caused me to miss a dive... -Andy

Gill Envy

LOL, you so funny! UM, yes, the finer points of the prism were damn impressive and caused me to do quite a bit of research on it. I liked most of what I found. The prism's needle gage that takes full advantage of the fact that o2 scensors are actually fuel cells, it's just super cool! it's kind of mind boggling that all rebreathers aren't employing this as a back up, these cells are producing energy, why not take full advantage of that on at least a back up gage. "look mom, no batteries!". The design of the cowling seems a bit wonky, the scrubber is about twice what i need, but I like the radial design, the manufacturer is still a lot further away than a two hour jaunt down I5, the number of meg divers in WA is growing exponentially, and that matters somewhat to me. In any case though, convincing the mrs's to give another eCCR a try was just out of the question.

Well, I do agree with you, but if you have not dove on the vision you might not know what you are missing. Seeing what we went through with my wife's unit would turn anybody off, luckily its extremely rare. Again, if it weren't for my wife's insistance i'd just slap a shearwater on our evos and then they would be very well sooted for even the remotest diving. Yeah, yeah, there would still be the OTU nanny, but I have a feeling that that is just a matter of time till it becomes permanently supressible.

As for integrated deco, i'm not that attached to it, it just turns out that I want a totally redundant set up and the Copis only comes with one handset...which is just fine with me, I love the idea that it's designed so that it can be a base unit and modified to the hearts content. there are even extra ports already in the head that lend themelves very well to being co-opted.

Anyway, we need to start looking into spring dates for the next indonesia trip. Ambon was very cool! oh, and your "2 live crew" avatar is in the works .

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Gill Envy

...Because I wasn't born with gills!
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abowie

All very well but you have to be aware that one thing you get here is the worst of both worlds too.

Say for argument's sake you take an eCCR and fit a CMF setup to it. You fly on the mCCR and only need to use the solenoid as a parachute if your PO2 drops below a certain point (pick 0.40 as a magic number). Great idea; if your CMF fails, your solenoid kicks in and tops up your O2, saving your bacon.

Problem is you get all the complexity AND all of the potential failure points of BOTH systems. Now this might be outweighed by the potential safety benefits. Or it might not.

It was interesting to read Mark Chase's comments moving from the Inspo to the KISS. Entirely understandable as you go from having it all done for you to having to keep an eye on, and intervene, yourself.

Personally I'm sold on the concept of the m(echanical)CCR.

Being a simple fellow, I look at something simple; death rates. Take 2 units that have (very approximately) the same number of units in use; KISS and Meg. I reckon there have been close to 10 deaths on the Meg. As far as I'm aware there haven't been any on the KISS. APD has something of the order of 5000 units in the field. Martin Parker himself said at Oztek 07 that they have an average of 5 deaths per year on their units. Now I have a wife, 3 small children and two dogs to support, and personally I would prefer to remain alive.

Having said that I'm currently not doing dives that I feel warrant the use of closed circuit and so I've sold my SK and am diving OC exclusively. This is because I dive shortish, shallowish tight caves at present where CCR simply offers no advantage.

As the opportunity to dive deep in some of our larger sinkholes presents itself in the next few years (60 to 120m range) I'll be looking toward CCR again, and it'll be mCCR.

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Andrew Bowie

Rebreather-friendly Buddy

jdicediver

The only limited experience I have with a rebreather was garnered during the Meg Mod 1 course, so please temper this post with forethought and your first amendment rights (for you Americans at least).

My new COPIS Meg, which arrived on May 12th, is configured as follows:

Standard configuration, with dual Apeks first stages, Worthington 19cuft HP cylinders on Tiger gear mounts, a fourth cell fitted to a VR3 in the Inhalation counterlung, a Portland Oceaneering backplate, Dive rite Rec wing, and an ISC Deluxe Harness. Pretty standard stuff.

For the record, I am going to change the wing to a donut style to eliminate any problems in regards to uneven buoyancy and gurgling noises in tropical locations. I currently use the wing for surface flotation only, and do not utilize it for flight pattern regulation while using a dry suit.

I have also determined a use for my 6cuft cylinder as a redundant 02 supply as plumbed, or quick connected into the loop with a pressure compensating first stage, or additionally, as stated in this post, it could be used for the short portion of a deep dive, below a depth where the IP of the CFO is exceeded.

I too, do see value in the “fly manual” philosophy used by eCCR divers; however I do question how much your life is at stake during any CCR dive as long as the P02 is always known. Now, before anyone jumps up to cut my throat, or gag me for such a statement, is it not true that a CCR can support life at set points between .40 and 1.6 quite comfortably for a discernable period of time? Pending forethought to the obvious concerns regarding deco obligation increasing as the set point variance is disregarded, PO2 ranges are quite liberal.

As long as the P02 values are maintained between these breathable limits (with precautionary knowledge calculating for changes due to increase/decrease in depth) there is no eminent threat of death (ETOD).

A redundant Po2 monitor (VR3 in the loop) and the COPIS now has a truly independent second Po2 display, for in line deco and independent, mental voting logic, while still running with the three cell design originally intended.

What is the problem with putting all 3 cells (R22D) on one monitor and adding a 4th (K1D) for redundancy and for in-line deco calculation. I see that this is one cell better than the Palagian design. This method runs on a truly independent PO2 monitoring system (VR3 with a Teledyne K1D) (*note different design). If the COPIS’s three cells go south, then bail out to OC is possible, with the actual setpoint values calculating true Deco obligations as calculated throughout the dive profile by the inline computer. The VR3 can also be set to monitor OC values after/during bailout.

Hooking up all three cells to one remaining functional monitor and continuing to dive on a trip would be like…what? Running a standard COPIS?

Hmmmm...again, I am amazed.

BTW...Choice great a COPIS is;

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Regards;


"Some people shouldn't dive...others shouldn't even get wet".

silent running

Yo G.E., after your experience, I understand the bit about no more ECCR. But FWIW, I think of the Prism and MKs as sort of inbetween E and M. I have only had to send my head back once when wet O2 corroded out my O2 side and solenoid. Other than that, I can't think of any routine reason why I would ever need to send it back. I suspect that very few MCCRs ever need to go back to the factory either, do to their simplicity. As for the cowling, remember that I had a protoype aftermarket plate which had not been finished yet and had no system for fastening the the cowling to it. The cowling is made out of fiberglass, very rigid and strong. It's survived my falling with the unit and my full weight several times with no breakage.

Ambon was great, but Thailand is similar in price and would be cool too. If you get your tmix ticket, we could do some of the wrecks in the Gulf and maybe some diving in the Andaman Sea too...

Looking ofrward to seeing the pix from the trip, -Andy

UWSojourner

I think GillE's reasoning is spot on. I very much appreciate your decision to change direction. Good luck to you and your wife.

bletso

Gill,

It goes to the root of human nature. Most HUD.s, rEVO included, are really secondary displays. Raw info has had decisions made on status etc. When it dispays different pulse rates, colors, etc, these indications are based on internal settings the machine makes, not you. i. e. rEvo assumes that if the PO2 is under .5 for 5 minutes, it shuts down.

Maybe, I am running that PO2. That would be my decision, and as long as it remains where I want it, my business.

I believe that the decision making is the divers responsibility, not a third party. I use two independent primary displays, both of which I can view simutaneously. If I could not view them at the same glance, then by human nature, I would probably start to rely on the one I could access the easiest and by default it would become a primary/secondary display configuration.

HUD's and displays like the rEvo funnel both cells to one controller. I would use the HUD as my primary display (human nature) and rely on the digital screen as a secondary. But, the HUD is being driven by the same circuitry, therefore no isolation between cells. If the controller goes awry, you loose all.

Don't get me wrong, the rEVO looks like a well thought out design and package, but IMO it is hindered by the funnel.

Using a system like the one I put together is two completely independent systems. Even the common case is devided into independent sections. The set points are run by me with real numbers, which translate into real values to my brain as regards PO2.

I have stated before and I might as well say it again, if you give a guy a crutch, he more than likey begin to rely on it. Buzzers, horns and other types of indicators are just such devices. One will dive and rely on the outside system to warn him of impending disaster.

Constat monitoring your PO2 is important to spot certain failure modes. I don't want to wait until the unit is telling me, OH, BTW, you have a problem.

I hope this hasn't been to confusing an expanation.

Dale

brinoz

Hi,

on the rEvo, you have two rEvodream's.
So you have always two HUD's you can seen in the same time, completly independant from each other.

Bruno

Stephane

Hello Dale,

That's a feature that can be turned off if you want. But you will have to shut down the rEvodream after your dive.

If the controller goes away, you still have a valid PpO2 reading on the display.

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Stéphane

rdmmdr

Eccrs are by nature, inspire operator complacency. The problem with the current designs are the hand off nature of those designs. As gill has said independent control needs to implemented. one side does the HUD and a hand set, the other side does the setpoint and a hand set. no mixing of the batteries they should be large enough to handle all of the power loads. no hot swapping of the controllers, the best controller underwater as proved by the kiss system is the human mind. Some of the designs in development out there are two cell only, for each side. that allows for complete Independence of the controllers. but you say how does that allow for three cell voting. it does not. but it allows for the operator to be informed that a cell has failed when either hand set displays a problem. those design force the operator to initiate a dil flush to determine what is going on with the cells. even with three cell voting you should be forced to initiate a dil flush to determine what is going on with the cells, on a single cell failure. because we do not know i we have two cells water blocked and only one cell reading right.


the basic thought behind the three cell system is that if a single cell fails we will be able to determine what cell has failed. but this does not take into account environmental conditions ,IE. condensation that could take out two cells at the same time. so we have to add in injection failure software in case the cells don't see the o2 injection. and the design thought that blowing dil on the cell faces to clear them is even worse because it just hides a design flaw that allows for the cells to become water blocked and will not allow for proper diagnosis of the problem.

As we look at the current systems out there, ask yourself, do you trust them?

controllers are just like a regulator if it fails you are done with it this dive.

we as consumers demand that the next piece of equipment has more bells and whistles then the previous piece. this is stupid. do we really need a car that can parallel park itself? no. instead of demanding that the manufactures spend money developing deco controllers, and by the way the are not doing doppler studies with them. they are just using somebodies else algorithms and hoping they got them right. we should demand that they spend this development money to ensure that the units currently out there are right, and will work every time. while it might be fun to drive to work in a lotus,. a chevy will get you there, and will get you there more often.

gill you said that you where disappointed that the inspro would not allow you dive the with a broken solenoid. my question is why would you want to risk your wifes life with a piece of broken equipment to save a dive. you would let her enter the water with a free flowing regulator, no. so why would you allow her to dive with a broken controller. by the way if you could convice my ex to dive with you go for it. as long as i am out of the country.

rick