What is "recreational" rebreather, and any recommendations?

[tbone1004]

Meanwhile, people keep posting pretty pictures on social media that everyone wants to emulate.

I've opted to let people like Kirill do that... I can't compete with that level of photography so I'll stick with surface selfies with buddies and have a gopro on me just in case something interesting happens.

 

[JohnnyC]

Just an FYI, since you specifically mentioned shallow, that's where rebreathers are the least value. That's also where they tend to be the most dangerous. Your unit will be trying harder to maintain your PO2 setpoint, your buoyancy will be more difficult, surface conditions would exacerbate those issues. Couple that with a big camera and a lack of focus and it becomes riskier.

That's not to say that it's not worth doing, but attacking the problem with a recreational attitude is the opposite of what that dive would really require. You've gotta be on your game when you're shallow on CCR.

 

[jstrang]

I would look at any of the fully ECCR rebreathers - I am Canadian so Ill plug the Shearwater Divecan rebreathers.
Simple to use if you are used to a SW computer.

The rebreather will definitely help with photos - fish just dont run away from you like they do on OC.
I have seen frog fish swimming up to me - not a care in the world when on a RB.
It will shock you to find out noisy OC diving is. It sounds like a large flock of seagulls. No wonder the fish just scatter.

Having said that I would encourage leaving the camera at home until RB diving is second nature - 100 -200 hours (probably a bit aggressive) would be the minimum number of hours diving it BEFORE you bring along a camera.

Any RB will have reasonable WOB and be fine from 20' to 100' - below that you'll need to add He to the mix to keep the WOB reasonable. Greater than a 100' add He. At depths less than 20' just takes practice keeping the counter lung volume low. If I'm diving less than 60' i'll just run the RB on 0.7 setpoint and still be able to do a 4 hour dive and not incur deco.

 

[ND5342]

I am interested in a rebreather for my underwater photography. Not interested in extreme tech or cave diving, more interested in the "silent" aspect.

So,what is meant by a "recreational" rebreather? What brands/models does this mean? Why and how are they simpler to use than a "non-recreational" rebreather? I want something relatively simple, where if there is an issue it warns me, I have a bailout valve connected, and can end the dive safely, as opposed to trying to "fix" the issue at depth.

Any advice to get my research going would be appreciated!

I initially was introduced to rebreather diving in the Navy with the Mk-16 in 1994. I fell in love with that type of diving but I was only at that command for four years and feel I just scratched the surface of the technology. After retiring from the Navy and my kids leaving the home I have had more time to get back into diving recreationally and go down the rebreather path. I was fortunate that a local university had some APD/ Silent Diving rebreathers as part of its scientific diving program. So with my tuition already paid for with other classes I was able to be trained in a mentoring style based on TDI instruction, with my only other cost being the sorb and TDI training materials. The Inspiration I dove was the typical tech/ Vision configuration with the DSV, a step up from the old Classic. I am so glad I was able to learn in this way as I did not have to purchase a rebreather without really having an understanding of what rebreather diving is and all the theories, types of equipment and why there are so many types and different designs.


I then tried a Poseiden VII with a BOV in its standard upright configuration and its simplicity of operation and I was impressed. I consider it the Mercedes of rebreathers. All the bells and whistles designed for comfort and ease of use. I had a chance to get into one for next to nothing so I took the plunge and organized some training with a PADI instructor who gave me the crossover. Since the unit I had was set for Rec I ended up doing the PADI Rec Rebreather and Advanced Rebreather. One thing I liked about the training in this course was the DVD PADI gives you for reviewing the skills. This course pretty much teaches you to bailout if you have a problem and since you are in NDL this should not be a problem. I like the Poseidon for its ease of use and the BOV is the bomb but I am not too crazy about repair parts and equipment add-on prices. The Inspiration/ Evolution units are already set up for deep tech diving and there are plenty in the used market. The Poseidon battery while a good point of contention makes it easier for your buddy to see if your rebreather is acting up which could be good for someone getting distracted by their photography.


I now have about 75 hours between the two rebreathers and this is my take on anyone thinking about going down this path:


1) Find a rebreather instructor locally that dives the way you do or want to and who has plenty of experience

2) Buy a used rebreather that instructor trains on, but have that instructor help you with your purchase. Better yet buy a used one through them if they have one. I recommend getting one with over the shoulder counter lungs and a BOV as I think these are the easiest to learn on. Not saying it’s not possible with back mounted counter lungs but I tried an Inspiration with the BML and it was a little more challenging to dump them and find the add valves. You are going to have a lot to learn as it is. There are a lot of Inspiration/ Evolutions, Optimas, Poseidons and Hollis Prisms on the used market at decent prices. Even if they need rebuilds you can still come out way ahead.

3) Dive the heck out of that rebreather and now that you have more of an understanding of the technology and are probably hanging out with rebreather divers you will start to understand which options are really important to you.

4) If at this point you are ready to go new, then go and do your try dives as now you will have more of an understanding to compare. You can sell your used one for a lot closer to the price you paid for it then a new one. Try dives to me do not make sense to a new rebreather diver. That is like test dives on a vehicle before learning to drive! The only thing IMO that would be worth it for is to decide MCCR vs ECCR.

5) If you plan on going on to learn deco and trimix (which to me is the whole point of these things) make sure the unit you buy new does not make it more expensive to go in that direction.

 

[Dominick Gheesling]

I've been working on a mental outline for an article on this topic. Two former students of mine along with a friend of theirs got lost in a cave last summer because they were busy ******* around with a camera and there was a recent double fatality in Mexico that cameras may have played a part in.

Meanwhile, people keep posting pretty pictures on social media that everyone wants to emulate.

Just let me know if you need any notes for the article

 

[kensuf]

Love ya' Dom. Hope you're feeling better.

 

[silent running]

I’ll chime in to say that generally, recreational CCR diving uses air diluent and you are supposed to stay within NDLs. If you rack up 10 minutes of deco it will be gone as soon as you start ascending. CCR is a huge advantage in this regard alone.

SCR is a total waste of time, if you are looking for silence and the best wildlife interaction you will be very irritated by your SCR when it burps up bubbles while you are having a great moment. I came through the Draeger Atlantis and went straight to CCR as soon as I found a US manufacturer I liked. And nitrox is not always available, O2 is available anywhere there is a hospital or welding supply place, which is everywhere. You can also bring or send ahead CO2 scrubber material. I have traveled to very remote parts of Indonesia doing this and had fantastic experiences. The main issue for most CCR divers who dive for the nature is working out dive logistics with the operators. I have found that once an operator saw I was competent and used my SMB, they usually let me dive by myself, and get in the water first and out if the water last, which makes a big difference in the quality of your dives. I also try to go in the opposite direction from the open circuit divers, they will scare away most big stuff if it’s in the area.

Diving in shallow water with a CCR is not that difficult if you do not change your depth a lot. That being said, an MCCR, or manually controlled PO2 CCR with an adjustable O2 flow as opposed to one with a solenoid and computer control of your PO2, will make diving shallow and with depth changes from surge easier as it does not hold a fixed PO2, and will only bleed in a constant rate of O2. You have to adjust the orifice to match your metabolism and general target PO2. This sounds much more complicated than it actually is. If you want to get really simple for diving shallow, you can get an O2 rebreather but your depth will be limited to less than 30’.

Finally, I do not consider CCR’s to be dangerous. Once you understand how your rebreather works and the failure modes of oxygen sensors, any problem you might have underwater will be solvable, and the huge efficiency benefits of a rebreather will give you lots of time to solve them. I have done several dives on CCR where I found myself in a difficult situation and would’ve absolutely run out of air and died if I were on OC. With proper training and experience, there is no better dive experience to be had, IMHO...

 

[uwxplorer]

Finally, I do not consider CCR’s to be dangerous. Once you understand how your rebreather works and the failure modes of oxygen sensors, any problem you might have underwater will be solvable, and the huge efficiency benefits of a rebreather will give you lots of time to solve them. I have done several dives on CCR where I found myself in a difficult situation and would’ve absolutely run out of air and died if I were on OC. With proper training and experience, there is no better dive experience to be had, IMHO...

Your opinion. It's like saying "guns are not dangerous, only crazy guys with one are". Well, accidents among the young gun owners or users (or friends. relatives) are not really going away, it seems. Transpose this to "not sufficiently proficient rebreather user", and you have a recipe for disaster. I believe it is important to hammer this truth in front of a potential victim of his own distraction. Now, I am not saying there is no place for recreation rebreather diving (I do a lot myself), but it is certainly no walk in the park (and lots of added cost and maintenance).
As far as dives where you would not have survived without a rebreather, are you talking about recreational dives (the OP's stated goal)? I hope not.

 

[broncobowsher]

Forgot about the pure oxygen rebreather. For really shallow stuff that is a good choice. But watch your oxygen loading.
You will want at least an Advanced Nitrox class to understand the limitations (and the freedom) of a rebreather. I wouldn't consider the typical Nitrox class to really be enough. A good start, but not enough.

 

[silent running]

Your opinion. It's like saying "guns are not dangerous, only crazy guys with one are". Well, accidents among the young gun owners or users (or friends. relatives) are not really going away, it seems. Transpose this to "not sufficiently proficient rebreather user", and you have a recipe for disaster. I believe it is important to hammer this truth in front of a potential victim of his own distraction. Now, I am not saying there is no place for recreation rebreather diving (I do a lot myself), but it is certainly no walk in the park (and lots of added cost and maintenance).
As far as dives where you would not have survived without a rebreather, are you talking about recreational dives (the OP's stated goal)? I hope not.

Yes, it’s my opinion, thought IMHO covered that.

Bringing guns into this is hyperbolic and unhelpful. Guns are designed to bring lethal force to bear on a target, rebreathers have no such purpose. I disagree with the notion that my rebreather is trying to kill me. If I do everything I’m supposed to, my Prism 1 will keep me alive as long as I am sentient.

I’ve never met anyone who thinks CCRs are a walk in the park, but their risks are manageable with good training, the right motivation and disciplined practices. “Not sufficiently proficient” rebreather divers would tend to be weeded out by the high price tag of the gear and training. I’ve been diving rebreathers since 1998 and all the RB divers I’ve met have been meticulous and serious about their safety. Do CCRs attract some envelope pushing daredevils? Maybe, but continuously and piously carping on about RBs being dangerous may actually attract more risk takers while also scaring away people who might get a lot of enjoyment from them. Without more people diving CCRs, the needed safety improvements and innovations will happen more slowly or not at all.

As for my CCR saving my life, again we come to the meaning of “recreational” diving. Is exploratory diving in PNG and Indonesia considered “recreational”? It certainly was by me and those I was diving with. There was no planned decompression, but neither did we plan on being caught in tidal down currents that pulled us to 60m+ in less than a minute and forced us to claw our way back up, hand over hand for 30+ minutes at maximum exertion. If the two of us were on single tank OC we would have run out of gas and drowned. CCRs give you time to get out of trouble whether caused by the environment or ourselves. That safety benefit alone outweighs their potential risks by orders of magnitude, IMHO...