Thinking of a rebreather

So I am thinking of getting a rebreather - either an SCR or an mCCR. Stupid bubbles. Fish no like bubbles. Me no like bubbles.

Anyhoo, my requirements:

1/ Modular and self-fixable/servicable

2/ Uses standard tanks

3/ Mainly for recreational depths

4/ Ability to use with my own backplate/wings (or any kind of BP/wings... no traditional BCDs)

The KISS Sport looks really good, especially for the price. Any other ideas or recommendations?

I was planning to take a trip down to the Red Sea later this year and get my training.

Vandit

Stay away from SCR. They have most of not all if the disadvantages from diving a rebreather and almost none of the benefits.

Since you have excluded ECCR, the following units deserve your attention:

Pelagian - Made in Thailand. Very small setup. Uses a needle valve. Very streamlined.

Kiss - well known unit but the breathing comfort is rather low.

rEvo - Very compact, great performer, can be converted to ECCR

In a months time (or so) DeepLife will release a new mCCR (for the masses). This unit is supposed to have excellent build quality, very safe and extremely cheap. Alex Deas mentioned a price around 995 US$. Probably worth waiting for.

Peter

SCR's make bubbles.

There are several questions you need to ask yourself before deciding. Travel vs. local. Ease and cost of getting scrubber material. Support and training. Blah, blah.

Two that intrigue me:

http://www.diverite.com/products/catalog/o2ptima/drt-1-fx

http://www.poseidon.se/

For some reason the link feature in my response won't work.

I got to admit I've been tempted by RBs, similar to you more from the thought of much less-limited bottom time at recreational depths than at the desire to 'go deep'... and of course for the quiet. But I've quailed at the thought of getting one at my current skill/knowledge level, and recognize the cost/maintenance burden of one when I only get 20-30 dives a year in if I'm LUCKY is just ludicrous.

If there really is a sub $1k RB coming out, I may have to re-evaluate that decision.

I'm currently diving a rEvo, my 7th ccr, and I have no desire to switch to anything else.

Its build quality is outstanding compared to the other rebreathers I've owned, and setup is extremely simple.

I don't think the work of breathing is quite as good as pelagian, but it is very close (and I have a clear chest). WOB is definitely better than both kiss units.

SCR's make bubbles.

 

There are several questions you need to ask yourself before deciding. Travel vs. local. Ease and cost of getting scrubber material. Support and training. Blah, blah.

 

Two that intrigue me:

 

http://www.diverite.com/products/catalog/o2ptima/drt-1-fx

 

http://www.poseidon.se/

 

For some reason the link feature in my response won't work.

Both of those certainly do not fall in the "self service" rebreathers group.

BTW. You'll find a video interview about the Poseidon rebreather on our website together with several others like the rEvo, the Inspiraiton, Sentinel, ...

I'm currently diving a rEvo, my 7th ccr, and I have no desire to switch to anything else.

Its build quality is outstanding compared to the other rebreathers I've owned, and setup is extremely simple.

 

I don't think the work of breathing is quite as good as pelagian, but it is very close (and I have a clear chest). WOB is definitely better than both kiss units.

Paul just released a kit to lower the WOB on the rEvo.

I took a look at the new Boris Sentinel the other day. It seems a very well engineered piece of kit with bags of redundancy. No one's saying anything bad about them and a lot of them are being trialed at NDAC - one of the UK's deepest inland sites. For me, the choice would probably come down to an Evo Vision or a Sentinel...

Kiss - well known unit but the breathing comfort is rather low.

 

Peter

I beg your pardon.

There are at least two wetpixel members who dive KISS rebreathers regularly, Doug Ebersole and myself. Ryan Canon use to dive a Pelagain, but he has recently switched to a rEvo, and says he likes it a lot.

We have done a few articles on rebreathers in the Underwater Journal.

In issue three, a sort of introduction to the Sport KISS.

Issue 6 a round up of various rebreathers on or soon to be on the market.

And issue 7, besides Doug Ebersole’s daughter Kim on the cover (also diving a Sport KISS) is a short on a day out diving rebreathers off Jupiter Florida during goliath grouper spawning season.

All three publications are available in the back issues, and they are all free. Each issue is a pdf file, which takes (depending on what internet service you) 5 to 25 seconds to fully download.

Also, another good site to talk to fellow rebreather divers is rebreatherworld.com

So come on over to the Dark Side.

I beg your pardon.

 

There are at least two wetpixel members who dive KISS rebreathers regularly, Doug Ebersole and myself. Ryan Canon use to dive a Pelagain, but he has recently switched to a rEvo, and says he likes it a lot.

Walt, I've dove with Doug, Ryan and you before, so don't forget to add me to the list!

I dive a Dive Rite Optima, which is an eccr that utilizes scrubber cartridges, instead of granular sorb - Quick to install and adds a very consistent scrubbing medium that will practically eliminate the risk of getting a caustic cocktail. The unit comes with great electronics and is built by a reputable company with a good track-record. The Optima also breaks down pretty good, so it's pretty convenient when it comes to travelying with it.

The only thing I'd caution you about, is the fact that the EAC (Extend Air Cartridges), although I love them and would not buy a unit that didn't use them, can make travel a bit more complicated, because they can be difficult to find everywhere, especially outside the country.

Definitely take Walt's advice and read those articles and visit Rebreather World - It's definitely a do your homework kind of decision!

BTW, I may be bit bias because I use one, but I'm a big fan of electronic rebreathers, so that would be my recommendation. Personally, I'd suggest taking a look at the Optima, the Meg or the Hammerhead.

Adrian

I beg your pardon.

Hi Walt,

I'm not saying it is a bad unit. But tests have shown that the breathing comfort is rather low compared to other units. Especially in certain positions, like on your back. Don't you get the chipmunk effect?

BTW. People are very bad judges of WOB. Test equipment does a better job.

The only thing I'd caution you about, is the fact that the EAC (Extend Air Cartridges), although I love them and would not buy a unit that didn't use them, can make travel a bit more complicated, because they can be difficult to find everywhere, especially outside the country.

 

Definitely take Walt's advice and read those articles and visit Rebreather World - It's definitely a do your homework kind of decision!

I really like the concept of the EAC cartridges. They lower the WOB and they are safer because there is no risk of the user screwing up his scrubber fill. But they are more expensive. I wonder how people will get hold of them in countries like Indonesia. It took me six months to get sorb organised for our last trip to Komodo. And with import taxes of 100% .....

My recommendation would be to try as many units as possible.

I got to admit I've been tempted by RBs, similar to you more from the thought of much less-limited bottom time at recreational depths than at the desire to 'go deep'... and of course for the quiet. But I've quailed at the thought of getting one at my current skill/knowledge level, and recognize the cost/maintenance burden of one when I only get 20-30 dives a year in if I'm LUCKY is just ludicrous.

 

If there really is a sub $1k RB coming out, I may have to re-evaluate that decision.

Hmmmnnn...

I'm not sure about this. I have a thousand+ dives, but can't guarantee more than 50-60/year. I was advised that it takes a hundred rebreather dives to acquire basic proficiency, and that they probably should be done without a camera.

As a physician, I am concerned about equipment that impairs your ability to respond (hypoxia or hyperoxia and hypercarbia) as part of the way in which it fails. Engineering is very solid in rebreathers these days, but they aren't fail-safe.

I thought that there wasn't much point in moving to a CCR unless I was doing 100+ dives/year, and that an SCR didn't address a photographer's needs. But I haven't made any use of my Trimix training, either, as helium is too expensive on OC...

My advice, as an outsider, is to go CCR when you can do a lot of diving, otherwise, go diving!

Tim

B)

PS

Watch out for the hammerhead unit! I dived Bikini (sadly, now closed to diving) with a pair of hammerhead-ers. They had endless electronic problems and missed dives, one abandoning her unit to go open-circuit!

Tim

B)

Hmmmnnn...

 

I'm not sure about this. I have a thousand+ dives, but can't guarantee more than 50-60/year. I was advised that it takes a hundred rebreather dives to acquire basic proficiency, and that they probably should be done without a camera.

 

As a physician, I am concerned about equipment that impairs your ability to respond (hypoxia or hyperoxia and hypercarbia) as part of the way in which it fails. Engineering is very solid in rebreathers these days, but they aren't fail-safe.

 

I thought that there wasn't much point in moving to a CCR unless I was doing 100+ dives/year, and that an SCR didn't address a photographer's needs. But I haven't made any use of my Trimix training, either, as helium is too expensive on OC...

 

My advice, as an outsider, is to go CCR when you can do a lot of diving, otherwise, go diving!

 

Tim

 

B)

 

PS

 

Watch out for the hammerhead unit! I dived Bikini (sadly, now closed to diving) with a pair of hammerhead-ers. They had endless electronic problems and missed dives, one abandoning her unit to go open-circuit!

 

Tim

 

B)

I want to make sure that I do not contribute to turning this thread into a "which rebreather is better" contest, however, I do want to make sure that you get a varying range of opinions.

Personally, I do not believe it takes 100 dives to acquire basic proficiency on a rebreather. I think it's more about the divers mindset, rather the number of hours logged. Even after 100 hours, some divers have no business diving a rebreather! Furthermore, from the very first dive following my rebreather certification, I have carried my camera with me and have no plans of completing a dive without it!

Diving a rebrether definitely involves monitoring many more functions and being much more aware of the status of your equipment, than open circuit, but that is overcome by being methodical in your approach, as will be taught during training. If you are diligent in your approach to diving a rebreather and use properly designed checklists, then a rebreather will actualy give you many more options to deal with potential problems, than you will have when diving open circuit.

I absolutely agree that rebreathers are not fail-safe, but most units are designed with multiple safety features that will either provide you with an easy way to monitor your systems and multiple warning systems to help you ensure that you have ample warning in the event that you are presented with hypoxia and hyperoxia.

As far as photography, rebreathers are a gift from above! Sure, a ccr will generally ensure that no bubbles are emitted from the device while diving, but a scr doesn't emit that many bubbles either, so I wouldn't rule it out, because they will both greatly improve your ability to approach marine life.

As far as the Hammerhead Rebreather divers having "endless electronic problems", my Optima utilizes the identical electronics as the Hammerhead and I dive practically every weekend and can't remember the last time I was kept out of the water because of a problem with the electronics. All electronic rebreathers will occassionally have some type of problem that, usually during your predive checks, might preclude you from completing the dive until you correct the problem, but this is usually done as a safety precaution. I unequivically do not believe that the Hammerhead Electronics can be classified as electronics that one should avoid; in fact, I think there pretty awesome!

Heading out for an all-day three wreck day of diving with my rebreather and my camera as we speak!

Adrian

Wow.. that's a wealth of information. No wonder I love this place - thanks, guys!

Scorpio - I've been doing through this decision process myself. I'd like to be able to both travel with, and dive locally, with this rig. If I had to pick one, local diving would be the most important (us islander types benefit from good tropical diving right at our doorsteps ).

Ease & cost of getting scrubber material is critical, as nothing is available locally - everything has to be imported. My plan was to add a large quantity of scrubber (or cartridges, in the case of the Dive Rite unit) to our regular dive store orders and keep them in stock.

Another issue is O2 fills - as these are done on another island, I'll need to gt 4-5 bottles of O2 and keep them at hand. So use of standard cylinders is a big plus.

Ryan, I'll check out that rEVO unit you mentioned. In fact, one reason I was considering the KISS was your recommendation of that unit on a WP thread from a while ago.

PCDiver - re. self service: well, provided I can get the parts kits, I can service them myself. I service regs and our compressors as and when needed, so getting in and twiddling a rebreather shouldnt be that difficult (provided I am able to get the appropriate training and service manuals - without that, I am not taking the risk: not with CCRs). However, modular and field-swappable is a big plus, due to our remote location. If the unit requires to be send off to the manufacturer for fixing, it is not an option.

PCDiver/SFLDiver - How long does one EAC cartridge on the DiveRite CCR last? And how long can you store dem cartridges? I can order them in bulk quantities - enough for 200-odd dives over 4-5 months, if need be, but I hope it is practical to do so.

Tim - I dive a lot (200+ dives a year), so practice and familiarity with the unit will not be issues, I think (hope).

Walt/PCDiver/Ryan - re. WOB: how bad is the WOB on the Kiss unit? Enough to create problems diving in strong currents? Can it be tuned somehow? Or is it only limited to chipmunk cheeks when turning onto one's back?

Walt - I'll be spending loads of time on the rebreather site you linked to: thank you for that.

One additional question/thought stream:

The reason I am picking an mCCR over an eCCR is mainly due to a stat I read that says that there are very few (or no?) fatalities recorded with mCCRs, and I still have vivid memories of reading about the latest Buddy Expiration deaths on Techdiver in the late 90s. Couple that with the fact that my breathing rate is pretty consistent across depths and task loading and so manual adjustments to the diluent should not be an issue.

The other reason for mCCRs is that it is more easily repairable - which is important for us.

However, were all else equal, I would prefer the "set and forget" mentality of an eCCR, as that would free me to shoot manually.

Now, I fully admit that this choice is based on my preconceptions, which are quite dated. I'd like something which requires minimal fiddling/futzing. But I am a responsible diver and I am quite happy to use my brain instead of relying on electronics, if that makes me safer. I am also happy to forego all the funky electronics and depth capabilities for something robust, reliable and easy to maintain.

Should I reconsider any of my assumptions re. eCCRs (especially re. repairs and field service)?

Anyway, the rEVO moves up on my list. Depending on the cartridge issue, possibly the DiveRite as well. I'll also research the other rebreathers and see what might fit the bill.

Regards,

Vandit

Hi Vandit,

So you are not totally averse to eCCR? I really like my Inspiration because I can keep my hands on my camera. BTW, they have improved safety wise since the 90's. :-)

Remote and strong currents ... the hybrid rEvo becomes a better choice.

It has multiple modes of operation.

1. pure mCCR (leaky valve)

2. pure eCCR (shearwater controller)

3. hybrid (both in use with either the shearwater as main controller or as a backup in case you forget to press the O2 button).

PS. I had my share of problems as well with my Hammerhead controller (metal version) and had to switch to OC on two trip because of unsolvable problems. Most of not all of these issues have been sorted out in the latest version. But I'm know diving a Vision.

Peter

EAC (Extend Air Cartridges): They are a really nice alternative to granular sorb – the stuff my wife says looks like kitty litter.

I’ve used them in the past with dragger dolphin SCR’s, and will attest they really do the job. Plus cleaning the scrubber when breaking down the unit is pretty much turned into no fuss, no muss deal. The only down side, they can be hard to come by outside the US.

Proficiency with a rebreather: True everyone is different, some take longer while others get it pretty well managed by the 2nd or 3th dive.

As for diving a rebreather with a camera, I think it is a sure bet that everyone who has chimed in and dives a rebreather feels it is really a non-issue.

When I went through my first rebreather course (Drager Dolphin SCR), the first ocean dive – camera in hand.

Inspiration (eCCR) second ocean dive - camera in hand.

Full Cave Course (not rebreather, but difficult none the less) ssecond dive – camera in hand.

KISS cross over course from Inspiration – once again, first ocean dive – camera in hand.

By the way the cover shot on UWJ-issue3.pdf was taken on that dive. The two other KISS divers is Doug Ebersole and my instructor Alan Studly.

Perhaps I’m different – but every instructor saw/knew that I make my living with a camera and therefore felt that if I was to be able to function efficiently with this equipment they had to see it now instead of assuming that I will get it later.

WOB (work of breath): That is a sticky wicket of subject. And yes, people are very bad judges of WOB. As for test equipment doing a better job in measuring it? That is a yes and no. Mechanic’s of the machines measure flow rate and resistance in simulated setting. What they can’t emulate is an individual’s physical condition, diving attitude (horizontal and streamlined or upright and moving through the water like an arthritic seahorse), to the position of the rebreather on their back.

Personally, I could not see the difference between an Inspiration’s WOB and a KISS’s WOB when I am trimmed out properly. The trick the KISS is having as close (pressed down) to back as possible. Back plates are not a good idea with this one.

And last, but not least. As tdpriest commented is the concern about equipment that impairs your ability to respond (hypoxia or hyperoxia and hypercarbia) as part of the way in which it fails. Yes, the engineering these days is very solid in rebreathers, but they aren't fail-safe. And the big killer with them is complacency.

Hmmmnnn...

 

I'm not sure about this. I have a thousand+ dives, but can't guarantee more than 50-60/year...

Yeah, I was exaggerating. I still 'lust' after RBs for all the same reasons the OP mentioned, but in reality a sub $1k unit would make me wonder "what corners are they cutting when everyone else charges 2x or more?"

I just need my long range financial planning (lottery tickets) to pay off so I can become an early retiree and dive bum. While I have spoken to a number of RB divers who actually recommend against getting tech/trimix certified and spending a lot of time doing open circuit tech diving before going RB (they think while it teaches you the right background science, it ingrains the wrong reflexes) I wasn't intending to belittle the training and attention burden of RBs either. I don't know if I'd wait 100 dives without a camera, but I certainly would get formally trained and want to test all bailout and emergency procedures more than just a single PADI-certification type demonstration before going back to diving mainly with an eye to the lens. At the least I gather each RB diver is different in terms of attitude (I mean in the water, not personality), breathing strength, swimming style, etc. so it would take many dives to 'dial in' your preferred rigging and trim arrangements, besides learning the RB mechanics as well.

Yeah, I was exaggerating. I still 'lust' after RBs for all the same reasons the OP mentioned, but in reality a sub $1k unit would make me wonder "what corners are they cutting when everyone else charges 2x or

Make that 5x to 10x more. There is a long story behind this rebreather. Do a search on Alex Deas, Open Revolution and Deep life.

Alex tries to revolutionise rebreather diving. If the market is big enough, rebreathers can be build quite cheaply but with extreme good quality. Incidently this rebreather could become one of the safest around.

OK, another retraction. Safe to say I will want a whole lot of justification as to why it's been made cheaper. But yes, I did peek at his site and do some googling after seeing your prior post, and it did look like they had a pretty good, scientific approach. And as you say, once RB production volumes go up, price can come down.

It's all fantasy for me though right now so I'll stop hijacking the OP's thread.

If the market is big enough, rebreathers can be build quite cheaply but with extreme good quality.

As everyone here who pays $125 for a port extension ring (a simple piece of machined metal) can attest, being on the ass end of the scaling curve can suck

Peter, thanks for that info. I think that rEVO unit looks the best for my needs. I particularly like that you can use it as a mCCR or an eCCR. I think I'll start with manual, replace my preconceptions and biases with actual knowledge and then make an informed choice on eCCRs. I'm looking at the 2L rig and titanium, if it saves some weight.

The $1k rebreather is another option if it is out by the time I am ready to buy. Am also going to starting haunting the rebreather forum.

Cheers,

Vandit

PS: Rtrski - feel free to hijack away - as long as the discussion is about the pros/cons of various rebreathers, I am all ears!