Rebreathers... why are they not more popular?

[padiscubapro]

Some CCRs actually have depth sensors, such as the Megalodon, PRISM, Vision-equiped APD CCRs, Ouroboros, Cis-Lunar etc. Either because they feature automatic setpoint switching and/or integrated decompression computers.

Dont forget HammerHead Equipped Inspirations, MK15s and KISSes

Dan,
I trained an instructor in Cincinati, He can probably do an intro for you on an Inspiration and also arrange to have a buddy of his show up with a Meg,, PM me if you want the contact info.

 

[trob09]

One benefit I know is that it also acts as your BC.

One more point to correct here...

While the volume of gas in the loop does provide lift and you can vary that volume to some degree, I don't know any rebreather diver who would advocate using the loop as a BCD.

I use a back-plate and wing with my Meg just like the backplate and wing I used for open-circuit trimix dives. The only difference is that the plate is heavier (thanks Fred T) and the wing is smaller.

T

 

[caveseeker7]

Dont forget HammerHead Equipped Inspirations, MK15s and KISSes

I'm trying to forget, but you won't let me. :linkz:

 

[Web Monkey]

See rebreathers on Deep Sea Detectives but that is about it. When I ask at the scuba shop or at the dive resorts I come up with nothing.

• More expensive to buy
• More expensive to run
• Require more user maintenance time
• Tend to cause death unless you really know what you're doing.
• May cause death even if you do know what you're doing.

It's the "death" thing that keeps me away. OTOH, there are a lot of people who use them regularly and love them.

Terry

 

[silent running]

Hello fookisan, you'll probably get more info from this line of questioning than you can possibly digest at first. But one thing that has not been mentioned so far and usually doesn't come up when dealing with RB heads, is the dramatic increase in the number and size of wildlife you will see with a CCR. That's the main reason I decided to get one, that and future tech diving objectives. If they're out there you stand a much better chance of seeing them than on open circuit. I've dived some of the same sights on OC and CCR and seen a dramatic difference. Believe me it was worth it. Just try to keep some distance between you and any OC divers!

 

[BigJetDriver]

• More expensive to buy
• More expensive to run
• Require more user maintenance time
• Tend to cause death unless you really know what you're doing.
• May cause death even if you do know what you're doing.

It's the "death" thing that keeps me away. OTOH, there are a lot of people who use them regularly and love them.

Terry

Terry,

Let me, if I may, try to answer your points in order:

(1) They are more expensive to buy at first. This cannot be argued.

(2) They are actually less expensive to run, IF your dives are deeper. For shallow dives, it is just a little more expense per load of kitty litter.

(3) After one is trained, and has a little experience, one can maintain a unit in the same time it takes to maintain OC gear properly.

(4) As for the "Death Machine" comment, even though it sounds like a GI3 flame-breath comment, it deserves a serious answer. The short but correct answer is this, just as an airplane is a complex machine that can be operated safely with proper training and procedures, so too is the RB. Any activity that puts one far out of the normal envelope, such as diving, brings risk. Re-breathers tend to be used in much more extreme diving than just pootling along the reef, so more risk is attached. That concept is not taken into account by some radical commentators, such as George.

Cheers!

 

[Web Monkey]

Terry,

(4) As for the "Death Machine" comment, even though it sounds like a GI3 flame-breath comment, it deserves a serious answer. The short but correct answer is this, just as an airplane is a complex machine that can be operated safely with proper training and procedures, so too is the RB. Any activity that puts one far out of the normal envelope, such as diving, brings risk. Re-breathers tend to be used in much more extreme diving than just pootling along the reef, so more risk is attached. That concept is not taken into account by some radical commentators, such as George.

Cheers!

The difference is that you can typically tell when something is wrong in an aircraft. You can also tell when your OC SCUBA isn't working (you're not breathing).

Although I've never used one, there have been a number of posts here regarding people who have died without ever knowing anything was wrong.

Terry

 

[caveseeker7]

The difference is that you can typically tell when something is wrong in an aircraft. You can also tell when your OC SCUBA isn't working (you're not breathing).

Although I've never used one, there have been a number of posts here regarding people who have died without ever knowing anything was wrong.

Terry, you are correct, the rebreather will let the diver breath even if the loop content is wrong. The issues are hypoxia (not enough O2), hyperoxia (too much O2) and hypercapnia (CO2 poisoning). O2 can be easily monitored, all currently available CCRs have three O2 cells and redundant readouts. How these are implemented differs from unit to unit. Leaves hypercapnia, which can generally be prevented by proper pre-dive procedures, adhering to manufacturer's duration ratings and absorbant recommendations. Diving deeper and longer than the scrubbers ratings is most likely the primary reason for CO2 related accidents and incidents.

All three of these problems have symptoms that should be felt by the diver. However, tolerance to increased O2 and CO2 differs as much from diver to diver and dive to dive as nitrogen narcosis. It can creep up quick enough and debilitate the diver that, while aware of the problem, he is still unable to react. That from those that have survived. What the fatalities knew or didn't know is probably hard to say.

But if you look at the available data, many accidents occured on solo dives, with modified units, some after ignored alarms, and plenty by divers diving past ther CC rating, some by divers diving past their unit's depth rating. Blaming these on the rebreathers is like blaming the OC rigs for a deep air fatality.

 

[fookisan]

Thanks to all for the information...especially the detailed answers from caveseeker.

One other question. Caveseeker mentioned electric vs manual rebreathers do manual rebreathers offer more safety since electric can go haywire?

Dan

 

[fookisan]

Hello fookisan, you'll probably get more info from this line of questioning than you can possibly digest at first. But one thing that has not been mentioned so far and usually doesn't come up when dealing with RB heads, is the dramatic increase in the number and size of wildlife you will see with a CCR. That's the main reason I decided to get one, that and future tech diving objectives. If they're out there you stand a much better chance of seeing them than on open circuit. I've dived some of the same sights on OC and CCR and seen a dramatic difference. Believe me it was worth it. Just try to keep some distance between you and any OC divers!

With such "deep" threads I print them out for reference. Too much for me to remember.

Dan