Rebreather's

For WIW,

For me the big issue, at present, with all rebreathers closed or semiclosed is still the lack of direct CO2 monitoring. I see now they are using temp monitors to gauge the condition of the soda lyme or other scrubber material. +/- whether this is a better indicator than color change. Granted you can't see the color change of the soda lyme inside the canister, but this besides the point because you are still not measuring your end tidal C02 which IS what you really want to know. Everything else is simply inference. C02 moniters are available but the problem is they are extremely sensitive to moisture---they use moisture traps---which make them impractical for use underwater. Want to make some money---design a moisture trap that works underwater in any orientation!

My two cents worth.

imasleeper

The dye indicator is a totally and completely unreliable means of monitoring after the fact whether the lime is still working. The temp sticks which are actually axial thermister arrays are very reliable in showing that the lime bed is active, an indicator it is still working, and where the heat front is, another indicator of how much of the bed is active.

Looks like Oceanic is going to anounce a CCR at the upcoming DEMA show.

Cronix,

 

If you are getting the Insp with Vision electronics, you should be getting WAY more than 3 hours on your scrubber.

 

Like the rest of us I ran my scrubber at least 4 hours until I got the temp stick......now in tropical I get 6.5-9 hours when seeing how long I can go....6.5 was the shortest, 9 the longest. Don't try any of that without a temp stick, and of course, the lawyers will require I tell you to stick to the manufacturers ratings.....

No sorry. My wife and I will both be diving a Classic Inspiration. 9 Hours is very long!!!

Cronix,

9 hours is long, I agree, that is using up the last bit of scrubber in shallow warm tropical clear water.....I don't recommend that.....With the Classic we were all running them 4 hours in temperate waters till some of us upgraded to the Vision electronics.

Having to look at either of the handsets every minute is lame.......with the HUD, that is eliminated although I look at my wrist controller every 5 minutes or so in addition to my HUD. I think the Vision electronmics gives me additional safety margins.....now I am waiting for AP to come out with their DSV/OC BOV

If I had to do it all over again I would get the smaller Evolution.....just much easier to travel with.

You are completely correct regarding the unreliability of dye indicators as a measure of activity in soda lyme after the fact. The key words being "after the fact" as the dye will slowly fade with lack of use. However what everyone assumes with the temp gauge is if the absorber is "functional" than the CO2 levels on the inspiratory side of the loop are at or near zero. The key word here of course is "assumes" since no one is actually measuring the CO2 levels on the inspiratory side.

Anyone who uses these devices has to be comfortable with this lack of data. I personally am not hence why I don't use them. But its perfectly reasonable for others to feel differently. Thats OK as long as its a learned and informed decision.

Cheers

imasleeper

Risk management has to be based upon the RELATIVE risks. Considering such, I am more likely to be killed driving to the airport to go diving or driving to a dive boat dock to go diving then I am from c02 exposure from CCr use.

Divers would be better off switching from open circuit to closed circuit AND wear a helmet when driving then they would be diving open circuit and never wearing a helmet while driving.

Reminds me of the moron California legislator proposing making it illegal (read revenue generation sophisticated shakedown scheme repackaged as "California Vehcile Code) to use a cell phone while driving but looking at a moving map GPS or tending to a screaming baby crapping, pissing, puking, farting and burping all at the same time while driving is apparently perfectly acceptable.

..now I am waiting for AP to come out with their DSV/OC BOV

Are you sure AP is creating a DSV/OC BOV? I want one.

Yes, they are and have been for quite some time...they're also working on a rebreather that will be called the Expedition, with a loop that is flood recoverable.......... but remember, AP stuff is probably the most tested rebreather products ever.....but that means they also take a long time to bring products to the market......all their stuff has to be run through CE approval....and for economy's sake to hold the price of products down, that dictates they run multiple items through at a time.

Look at how long they took to develop, prototype, test, refine, test some more, then finally produce the Vision electronics......it was years....and was it worth the wait? Hell yes!

Reminds me of when I was about to buy a Howell ADV...I heard AP was working on one, and I knew it would be smaller and lighter with better parts support, so I held out, and boy am I glad I did, Bob is nowheere to be found.

Rumor has it Oceanic will be introducing their CCR this DEMA show....

Just wondering if anybody has any problems with the breathing loop hoses getting in the way (more than with and OC reg) when looking through DSLR viewfinder.

I'm just about to take the plunge for an Evolution.

Just wondering if anybody has any problems with the breathing loop hoses getting in the way (more than with and OC reg) when looking through DSLR viewfinder.

 

I'm just about to take the plunge for an Evolution.

For me that's no problem. I use an Seacam housing with S45 45 degree viefinder.

But I tried an Ikelite last weekend. That's not working. I could not get a good view because my rebreather moutpiece was in the way.

So it al depends on which housing you are using.

I honestly don't notice the difference between OC and CC when it comes to seeing through the viewfinder, that's with a standard aquatica A20.

I have no problem using my Sea&Sea housing for my Canon 300D while CCR diving.

Today is the day. My I am getting my second Inspiration today. My wife will start her ANDI Level2 course soon. Can't wait to have a buddy who can stay down as long as I do.

I've only got about 100 hours clocked on a CCR (KISS), but I've found it's incredibly useful in some instances. Going deeper than normal air OC is one, hanging out with fish for a long time is another.

I agree that fish are not magically going to let you approach just b/c you're not blowing too many bubbles (that was one myth I rapidly dispelled when I tried the CCR), but if you're good with fish on OC, you can be even better with CC in many cases. I qualify "in many cases" b/c sometimes, the fish just don't care what equipment you're using!

And, as pointed out by someone else, it's actually a lot more difficult to stay in control with CC than with OC. Or perhaps, it's just that breathing on OC is second nature now, so the suffocating feeling of being on a CCR can be disconcerting, and staying neutral can be an effort sometimes.

When I'm on CC for a while, I find I need/ want to do a few OC dives. It's a liberating feeling to blow bubbles! Then I want to go back to CC, b/c probably the thing I like most about diving on a CCR is that you stay a lot warmer than on OC, esp over many days of repetitive long dives.

I just switched to CCR (Optima) this summer after 25+ years of OC diving of all types. I do see many benefits and not much in the way of a downside except cost of admission. As far as gas savings are concerned unless you are doing a few trimix dives per week every week you arent going to make back the cost of the breather.

I do find diving CCR warmer here in the NE. Our bottom temps are generally in the high 30's and I get out of the water with out feeling the chill where on OC mix I did. Yes I dive a drysuit.

Getting it ready for diving may be considered more time consuming but with 3+ hours of duration on one setup I can go diving for 2 days and do nothing to the rig once it is put together and on OC I would either be switching twinsets out or looking for fills.

My back likes it much better than a twinset & I find getting out of the water on rocky slippery shoreline much easier and safer than with tanks, and climbing a pitching boats ladder is a breeze.

I know some divers find the bouyancy an issue, but I like it better. Once you figure it out it is easier to stay in position vertically than with OC since your bouyancy remains the same whether you are inhaling or exhaling it makes no diff. Granted you do have to know how to dial in your bouyancy correctly and not be over weighted.

One other upside that isnt discussed often is the insurance you have have with a 3 hr. duration. If you are on a dive that your either must or wish to extend your BT,you can without worrying about how much gas you have on your back, and making changes to your deco schedule is easy in most cases since you are effectivly caring a blending machine on your back.

You also asked why we chose the unit we did. I picked Optima for the ease and safety of the Extend air cartridges (I am sure that will open a debate) and the strength of Dive Rite and the support available in the USA and abroad. I have a friend with an Inspiration that is about 3 years old and he has canceled, or aborted more dives than he has made with it becasue of problems with the unit. Which in itself is frustrating but the horror stories he tells of trying to get things resolved just adds insult to injury.

Nemo

I used both a Kiss Classic and a Kiss Sport for a couple of years. I am a very big fan of the classic, somewhat less of the sport.

I had a lot of trouble with the Kiss DSV obstructing my ability to view the viewfinder. I switched to the snog valve, which helped. If you have one of the Seacam or Subal magnifiers, this would be a non issue. Switching to the snog (a valve that allows you to add o2 or dil with your tongue) also eliminated the POS paragon second stage in the DSV, which was unreliable.

There were some chincy things about the sport that I think have been ironed out ( was diving a single digit serial number). I did a giant stride in CA only to find that the velcro strap that held the counterlungs & scrubber cannister in the toaster-box had broken, and they were all floating above my head... I replaced that.

My biggest concern, and the reason I stopped diving the sport, was breakthrough. Twice, in high current, I broke through the scrubber. I don't think I would have on the Classic. I dive enough on my own that this scared me.

I also constantly battled with my displays in both units. I had 2 redundant sets of the original style, and had a problem on nearly every trip. The first batch of v2 displays I received were problematic, too, but were replaced by Jetsam before I sold the rebreather.

I'm shopping again this year at the dema show. I really like the M-CCR philosophy. I'll probably end up with a Classic Kiss and some kind of aftermarket electronics. This unit is very interesting to me, though:

http://www.rebreatherlab.com/index.htm

I don't mean to sound too negative, I am a fan of the kiss and of Jetsam. Their pros and the benefits of the kiss rebreathers are listed all over the web. I think I was onbaord with the sport a little too early, and needed to give them some time to work out their kinks.

I'm really enjoying my YBOD (yellow box of debt!) and have reached the stage where I far prefer it to OC diving. 20 years on OC with no problems and now I find the bubble noise and breathing effort really annoying...

Here's the problem... planning a trip to the southern red sea for easter 2007. Equipment I wish to take is:

D70 + batteries + 4 lenses + charger + speedlight + laptop

Housing + stobe housing + dome + flatport + arms + clamps + adapters

S45 + batteries + charger

Housing + strobe + arms + clamps + adapters

Inspiration CCR

Wetsuit + fins + mask + snorkel + computer + reel etc etc

Travelling from SA to Egypt on cattle class the restriction is 1 carry on (<7kg) and one hold item (<22kg) which makes it possible to take the cameras or the CCR but not both...

Jeez but this gear thing get complicated after awhile!!!

Is anyone having any problems with an Ikelite viewfinder (or similar) and the size of rebreather mouthpiece and hoses?

ie. does it get in the way.

I know someone mentioned issues with a Kiss, but is anyone got anything to say about an Inspo/Evo setup and flat viewfinders?

thanks, ds

Is anyone having any problems with an Ikelite viewfinder (or similar) and the size of rebreather mouthpiece and hoses?

 

ie. does it get in the way.

 

I know someone mentioned issues with a Kiss, but is anyone got anything to say about an Inspo/Evo setup and flat viewfinders?

 

thanks, ds

Can't speak to EVO, etc, but I have 100 dives or so on a Draeger Dolphin with an Ike D70. I have to take care how the weights are distributed on the hose, but other than that, it's been okay.

I've been on many trips with CCR divers, and don't see a large advantage to that greater complexity for me. I do not have the monitoring capabilities they have, but the simplicity of the rig is appealing. When descending or purging, the bypass valve -- which is very much like an OC demand valve -- needs to function. At depth, the only moving parts are the two check valves in the mouthpiece. If you meter your FO2 and check your orifice rate, gauge your consumption realistically, and dive a reasonable plan, it's fairly trouble free -- and easily gives dive times to 100 ft that are as long as I'd want. Of course, it is possible to breath these units to too low PO2 if swimming hard, and one must consciously exhale through the mask in such a case.

I take about 10-15 minutes predive (FO2, flow rate, pos, neg, pressures), plus less than 1 hour once a day repacking and cleaning, in moderate water temps (Cocos, etc.). That seems a good tradeoff for abundant gas and fewer bubbles. The closed circuit divers appear to spend much more time, and also to have more difficulties with their equipment in the water -- and many of the CCR divers have been clearly expert, so it's not a matter of carelessness or gear obsession.

I like it. I just wish there were more places that supported it easily, as it is hard to travel with tanks and sorbent.

No one seems to have said anything about the people who should be and should not allowed and not allowed to use these systems. Of course those who have takent eh course want to sell courses and rebreathers and don’t give a damn, all they want to do is sell the kit and the course.

Here is my input for what it is worth -- Open circuit scuba is easy to use, anyone can simply put it all on, get into the ocean and you’re off, yeah we need to know the limits of using this, though it in general the system is fairly foolproof. Rebreathers require a certain degree of technical knowledge, much care and attention to this piece of life support equipment and constant monitoring of the unit. We have all seen how many divers don’t even check their air gauge on a regular enough basis, we’ve seen divers who miss the odd safety stop, we’ve all seen recreational divers making a whole bunch of mistakes that with regular open circuit may not be all that life threatening. It is a fact that to use a rebreather you need to be much more careful in the water and with your kit. Then you go an throw a camera into the mix too, oh a recipe for disaster in the making for sure. How many photographers have we all seen, we all do it, those who do not prep their cameras well enough, imagine having to prep your camera and your rebreather for every dive. Not everyone’s cup of tea!

I personally think that many divers should not use rebreathers, they can be very dangerous indeed for those who are not equipment geeks. Well of course I don’t mean this as a bad thing, just that the user needs to be very careful and have a much better understanding of this piece of kit. There have been way too many deaths and near death incidents with rebreathers by people who simply should not have been using them.