900 times more deadly than OC?

[InTheDrink]

The reason I was thinking of a rebreather course was for trips where bubbles might spook sharks as well as to stay down longer and deeper that OC Nitrox might allow. There will only be a handful of places I go to like this (e.g. Cocos Island). In a few years I hope to be able to devote a lot more time to diving, as in most of my time, and at this point I think a rebreather might make sense where other types of diving (penetration) and staying down longer may have more significance for me. From what I've read on this and other threads - as well as Jill's (rebreatherpro) podcast, it seems that doing rebreather for the sake of it isn't a valid reason; a rebreather is a tool to assist for specific kinds of tasks. I don't think a few shark trips would meet this criterion.

Secondly, from my buddy, who has done a rebreather course and ordered an Inspiration, I really didn't get the feeling that rebreather's were necessarily technical diving. Yes, probably says a lot about my experience. But reading here it certainly appears that rebreathers are indeed technical and would constitute technical diving.

I am definitely glad I checked out this forum and this thread as I may well have walked blindly into a pursuit clearly outside of my current abilities and into hazard. I see my buddy next week and I'll discuss with him to see why he thought a rebreather course would make sense for me - he is a very safety orientated and cautious diver so he will doubtless have a view on this. If it's anything interesting I'll post.

 

[wedivebc]

Not many dead people had check lists.
Jill

Intrestingly Leon Scammahorn told me not one meg fatality had filled in a checklist even though it is an essential part of megalodon rebreather training.

 

[Mr.X]

Mr X. Thanks for the post. I did notice myself that the incidents mainly seemed to be a decade or more ago. Any way of finding out what improvements have been made, beyond training - i.e. hardware and software - for the Inspiration.

My pleasure with regards to the info. I wondered much the same about RB's when I first trained on the Inspiration in the UK...just a few months after some of the first incidences. Was I playing with a piece of kit which had inherent issues? Was the YBOD a silent killer? The one thing that I discovered whilst taking my coursework and learning on this unit was that RB diving really, really required:

* Being aware of personal limitations - this wasn't so bad for me as I was a low- visibility diver. On my first dive near Portland we did manage to lose track of one of our Inspirations divers on the first dive due to abysmal viz. in the harbor.

* Perform complete checks and never take a shortcuts with regards to setup, preparation & maintenance

* Constantly monitor my PO2 - I manually control my PO2 on my ECCR's these days

* Always carry bailout. Some old timers (OC trained) dove "alpinist" style...not so good

* Stay physically fit - maintain excellent cardiovascular fitness and don't get a gut (omentum) which suggests a body more prone to heart problems. A lot of middle-aged guys may not always be cognizant of the issues related to body fat & severe-to-fatal clots.


That being said RB's are useful tools for specific jobs, or missions. These days most of my diving has reverted back to technical OC. In fact, I convinced an all RB team to revert back to OC for convenience and less down time on the job. We had too many issues on the surface related to failed electronics. That being said ECCR electronics often have gremlins associated with them...and get massively in the way of getting a job done. However, when I am filming fish & being paid I will take a ECCR. The lack of bubbles makes a HUGE difference with fish that are easily spooked by bubble noise and the video editing process where bubble noise is a distraction.

Best,

X

 

[Mr.X]

Intrestingly Leon Scammahorn told me not one meg fatality had filled in a checklist even though it is an essential part of megalodon rebreather training.

??? Did he mean manually filling one out for the intended dive, or just following the Meg flightlist? Curious.

Andrew Driver a multi-unit RB UK instructor trainer uses a mnemonic method called "two's." This secondary / redundant checklist/flightlist ensures that the gas is on (two valves on), two gauges showing pressure, scrubber is working (2+ min. pre-breathe), all ad valves firing (dil & oxygen) etc. prior to the diver splashing in. Smart method.

X

 

[wedivebc]

??? Did he mean manually filling one out for the intended dive, or just following the Meg flightlist? Curious.

Andrew Driver a multi-unit RB UK instructor trainer uses a mnemonic method called "two's." This secondary / redundant checklist/flightlist ensures that the gas is on (two valves on), two gauges showing pressure, scrubber is working (2+ min. pre-breathe), all ad valves firing (dil & oxygen) etc. prior to the diver splashing in. Smart method.

X

The meg checklist involves manually filling out a list and initialing each step as it is complete. None of these exist for any RB victim on a meg.

 

[grazie42]

I think the key for any new RB-diver (like myself) is to set firm limits, from the start, and stick to them...

I´ve promised myself not to:
-take chances on sorb
-dive with a known fault
-dive without going thru the check-list
-dive without adequate bail-out
-go "deep" until after 50hrs on the machine
-get lazy about checking po2

As long as I stick to these and maintain a healthy suspicion of my unit I think I´ll be ok...

 

[InTheDrink]

That being said RB's are useful tools for specific jobs, or missions. These days most of my diving has reverted back to technical OC. In fact, I convinced an all RB team to revert back to OC for convenience and less down time on the job. We had too many issues on the surface related to failed electronics. That being said ECCR electronics often have gremlins associated with them...and get massively in the way of getting a job done. However, when I am filming fish & being paid I will take a ECCR. The lack of bubbles makes a HUGE difference with fish that are easily spooked by bubble noise and the video editing process where bubble noise is a distraction.

X

I think that's a very good point too - hassle factor and risk of day of dive kit problems. I would imagine it's somewhat easier to swap 'bits' about on OC. If your eCCR is having an off day I guess that's it and hope the book you brought is decent. Probably a book on how to fix eCCRs.

And nice to hear that my primary motivation, lack of bubbles, isn't as silly I thought

J

 

[InTheDrink]

Mr X says:

"* Constantly monitor my PO2 - I manually control my PO2 on my ECCR's these days"

Just curious as to why you've opted for manually controlling this? thx

 

[Mr.X]

Mr X says:

"* Constantly monitor my PO2 - I manually control my PO2 on my ECCR's these days"

Just curious as to why you've opted for manually controlling this? thx

The silence of the CCR is wonderful. The difference can be night and day when it comes down to "closer" encounters and filming. Eel, jawfish, octopus etc. act almost naturally and you don't have to hold your breath to get those close shots. Also, when I don't have students I have experienced "zen-like" moments where all you hear is your breathing and the slight movement of the counterlung. Dave Sutton termed that experience "manfish" and I certainly relate. To be PC we could also use "merperson."

I dive several types of RB's and appreciate the KISS style RB's for their simplicity. During ccr instruction we teach manual ad and maintaining a steady PO2 setpoint (typically 1.2 @ depth). I am so used to manually injecting because of the KISS style that I do that all the time. Manual inject also saves battery & solenoid. I have had to replace several solenoids on Insp. Meg. Of course, when it comes to mind-intensive/labor intensive work I am happy to know that I have full ECCR backup and often let it fire to my desired setpoint. Comforting parachute that auto. setpoint, but never 100% trustworthy. That being said, I use a independently circuited HUD. It saves me from always looking at the handsets when filming, supervising etc. Cis lunar was the first unit with a HUD and buddy light - innovative thinking ahead of the curve.

X

 

[wedivebc]

I have had to replace several solenoids on Insp. Meg.

Wow that's amazing. You must do a lot of dives. I have yet to see a meg solenoid fail in real life.