With those stats you posted it looks like the rebreathers just kick ass over regular scuba.

So that leads me to the next question (and you can ignore it if I am being a pain ):

What are the different types of bad things that can happen with rebreathers? I always thought it was just the 30' limit but now with 375' it appears to my novice thinking that rebreathers seem SAFER. LOL! So edumacate me on what can go wrong with a rebreather.

BTW, RR did you get your scuba bubble with the military?

Thanks for being patient!

Ok nevermind, I just read about rebreathing technology. Here is why the shit is so dangerous:

What are the disadvantages of Rebreathers?

Discipline and Training

All kinds of rebreathers have certain specific complexities which introduce forms of risk not experienced by scuba divers. The fundamental difference between open-circuit scuba and rebreather systems is that on scuba, if a diver can breathe and is not outside well-established depth limits, the breathing gas is going to be life-sustaining (assuming the cylinder was filled properly). If there is a problem with an open-circuit system, the problem is usually very self-evident to the diver, so the diver at least is aware of the problem and can takes steps toward a solution.

With rebreathers, however, the breathing gas may be dynamic, and thus the oxygen concentration may drift out of life-sustaining range within the course of a single dive. In the case of oxygen rebreathers, if the breathing loop is not adequately flushed prior to commencing the dive, the fraction of nitrogen in the breathing gas may be high. For oxygen rebreathers with passive-addition oxygen control systems, it is possible that the diver may breathe-up all of the oxygen in the breathing loop before the oxygen addition valve is triggered, thus leaving only nitrogen. In the case of semi-closed rebreathers, oxygen concentration in the breathing loop depends on diver workload. Under certain circumstances, especially during high exertion and/or during an ascent, the oxygen concentration in a semi-closed rebreather could drop to dangerously low levels. The inherent weakness of closed-circuit rebreathers is the reliance on electronics to control the oxygen concentration in the breathing loop. As any underwater photographer knows, electronics and water (particularly salt water) do not mix. Indeed, closed-circuit rebreathers have earned a somewhat notorious reputation as being "unreliable", largely due to failures of the electronic O₂ control system (leading to either too much, or too little oxygen in the breathing loop).

These problems can be largely avoided if oxygen rebreathers are adequately flushed with pure oxygen prior to a dive, if the gas supply rate of semi-closed rebreathers is adjusted carefully and the breathing loop is flushed with fresh gas prior to an ascent, and if multiple redundant oxygen sensors and oxygen control systems are incorporated into closed-circuit rebreathers. Unfortunately, symptoms associated with hypoxia and oxygen toxicity cannot be regarded as reliable precursors to black-out. Therefore it is ultimately up to the diver to take steps to ensure a continuous life-sustaining gas mixture in the breathing loop at all times. This level of discipline requires a great deal of discipline and training. Thus rebreather divers must have a higher dedication to equipment maintenance and operation than is generally required for open-circuit divers. Furthermore, rebreathers are generally more complex devices than open-circuit scuba gear, which also accounts for why they require more training time.

"The degenerative and loony should never be denigrated but, rather, thanked. In their absence, the rest of you would be obliged to fill congressional seats... positions naturally unsavory to the sane and honorable."

Thorax

Roger Steve, many sport divers don't want to go through the hassel or the expense.  As for malfunctions some RBs are better than others at telling you something is wrong, and some are also better than others at providing options to the diver to correct them at depth during the dive.

IMO for certain applications beyond sport diving some systems out there are truly amazing.  I've dove an OR and SCR once and I liked them.  I know the Halcyon RB80 is a great system since I know a close friend and he swears by it and is alive after over 100 dives with it.  He is a scuba instructor and recently also became especifically an RB80 instructor.  RBs are showing up more because of their improving safety record.  Some of those articles are a bit harsh because they have to be.  Same as when in the 60s and 70s divers with no cave penetration training were entering cave systems with scuba and never coming out.  Then the warnings started and cave dive training was developed by a number of organizations and deaths in cave systems became almost unheard of.

Pete, I became interested in scuba after completing the 75th Ranger Recon Detachment's 3 week scout swimmer program at Tyndall AFB, Florida back in the summer of '88.  After that course I got certified as a civilian diver by the Green Beret Scuba club at Ft. Lewis, a club that no longer exists.  Some green berets taught NAUI courses and sold equipment right there on base.  Right after the scout swimmer course the 75th dangled a slot for the SF Combat Diver course at Key West ANS in front of my face to get me to re-enlist but in the end I opted for a nice piece of a__ that was waiting for me back home and college.  My summer of '89 ETS from active duty cost me my CIB, mustard stain, 2/75 combat scroll (Opertation Just Cause - Panama), and my scuba bubble.  But I sure had fun that summer after completing my first 4 years of honorable service with the army.

I've been diving since '88.  In 1995 I became a NAUI scuba instructor, instructor-trainier (1997), and course director (1999).  In '97 I also became a scientific diving instructor with AAUS ( http://www.aaus.org ) and dive safety officer (DSO).  I'm also an oxygen first aid instructor with the Divers Alert Network (DAN), and I'm trained as a hyperbaric chamber operator by Hyperbarics International out of Key Largo, FL.

As for the 30 foot limit for RBs that holds true for 'pure oxygen' systems only, not for nitrox or mixed-gas rebreathers.  When you breathe pure oxygen out of a scuba or RB system you cannot descent past 25 feet because of the danger of oxygen toxicity at 2 atmospheres (2 ATM) or deeper.

Military SOF divers with the Rangers, SF, SEALs, TACP/CCT/PJ, Delta, and Force Recon all learn to dive scuba and the LAR-V pure oxygen RB.  When on dives using the LAR-V since the system produces no bubbles their swim can be shallow (between 10 and 25 feet) for the purpose of tactical/undetected infiltration.

Navy EOD divers learn to dive scuba as well as the MK16 mixed-gas CCR.