Is it too early for me to get a rebreather??

[Hoosier]

The risks (particularly on CCR units) of going into hypoxia or hyperoxia are real. And yes, you do use a double setup, meaning you might need to bail out. Gas sharing with a rebreather is also a significant challenge. You need to re-learn buoyancy control on a rebreather as open circuit techniques no longer work. No more lung control of buoyancy. You need to learn how to purge water out of the loop and handle some of the idiosyncratic issues with each unit. This is why most manufacturers will not sell the units without the new owner taking trainnig.

There is a lot of new stuff to learn, a lot of stuff to keep an eye on. If you're busy worrynig about your other issues or are not truly comfortable in the water, adding the complexities of a rebreather might be too much.

At least this is how it was described to me when I asked, by a man who owns 6 units!

That's what I know. CCR requires a lot of new learning, not totally dependant on previous OC training. As I remember, the new CCR diver can take a nitrox and advanced nitrox course with CCR training together. CCR diver doesn't have to dive with the double rig before. I am not saying it hurts or it is meaningless.

I believe that most critical factor to get into RB world is a finance, not a previous OC skill

 

[PerroneFord]

Yea, maybe so. All the same, I think I'll wait.

 

[caveseeker7]

That's like saying you need a driver's license to fly a plane ... because you taxi on wheels. Why would you need to have trimix certification if you're not diving trimix?

Or deco procedures? Every initial RB certification that I'm aware of restricts the diver
to recreational limits, 40 msw/130 fsw without deco.

What is it with twins? Like saying before you get a drivers license to haul your gear
around in a car you have to prove that you can push, pull and carry it the same distance. The whole point of a rebreather is not having to use two, three, four, five or more huge tanks. If you're diving twins, there better be a rebreather in between.

What you need are good bouyancy skills, a solid understanding of O2 enriched gases
and the right mindset. With most rebreathers you'll need to be able to handle a bailout tank. A good class like ANDI's CSU includes the latter.

 

[PerroneFord]

Nearly all rebreathers I've been exposed to use trimix and oxygen. I know some of the SCR's don't. So wouldn't it seem prudent to be trained on trimix first? At least for CCR instruction?

Additionally, why on EARTH would any rebreather diver want to spend $4k-$20k on a unit to dive within the AOW limits? Doing decompression diving (longer bottom times) is the major point of diving with a rebreather. Unless we are talking about a unit for scientific study or use for photography/video work. And even then, I couldn't imagine ponying up $10k for a Meg so that I could do 60ft 55 minute dives.

I don't think there is any great mystery with twins other than they allow the open circuit diver to dabble in the world of longer bottom times, decompression, and introduce a bit more task loading in the case of valve shutdowns and such. I can't see any direct coorelation to moving to rebreathers. My previous comment about using doubles was only in the context of being to be able to enjoy longer, or deeper dives.

 

[Hoosier]

Not all of them!

All owner who has a sport car doesn't drive fast. There are many benefits to use RB except going deeper as you know.

In the rec. limits, we can expect a long bottom time without a deco procedure.
There are a lot of remote places (no air source) where the dive isn't approachable in the world. In this case, RB is more practical than bring a lot of tanks.

Just my 2 psi. I plan to get into RB world soon.

 

[PerroneFord]

How do you expect to get a long bottom time without decompression procedures unless diving a very high ppO2 mix? Without the trimix, you're diving the same nitrox gas an open circuit diver is using with exactly the same NDL profiles.

Or am I missing something?

 

[padiscubapro]

How do you expect to get a long bottom time without decompression procedures unless diving a very high ppO2 mix? Without the trimix, you're diving the same nitrox gas an open circuit diver is using with exactly the same NDL profiles.

Or am I missing something?

You are missing alot..

With a RB (CCR not SCR) you are always using the optimal po2, on ascent your oxygen content goes up (thats why I'll ALWAYS take a CCR over an SCR).. You can do some real serious multilevel dives by "skirting" the no deco limits.. and since the loop gets richer as you go shallower, you actualy begin to offgas considerably when the proper levels are chosen.. I have done 3 hour+ dives starting at 40m and working my way up without ever going into deco..

Once you start doing deco dives, its not uncommon for a profile that requires a CCR diver to do 30 minutes of deco, that an OC diver needs 2x that...

BTW.. I'll take a new diver with limited dives ( as low as 50 for now... EVentually we will train divers straight from CCR without OC, and I know of 1 diver that l;earned from day 1 on an inspiration... ) thats confortable in the water over an old salt to train on a CCR ANY day.. The experienced diver has too many bad habits that has to be unlearned..

 

[Caver95]

perrone, wait untill your doing the diving to coment on it. if someone has 14 ow dives and wants to cave dive they should get the trainning and dive how they want to dive. RB diving is a whole other ball game, I dont eventhink it is the same fargin sport. if you have the means, are not a complete idiot, and comfortable in the water they should have at it.
Flying a plane for the first time is really tuff, lots of stuff happening all at once really fast, but you get the trainning to deal with it and progress to flying by yourself.

 

[PerroneFord]

Hey, I consider this interactive learning. I don't mind being wrong, and am not trying to even PRETEND I understand rebreather diving. Learned somethnig new here today which is cool.

 

[caveseeker7]

Perrone, Joe already gave you some insight in regards to the deco.

Requiring experience and training using twins before using RB is equivalent to requiring trimix before using twins. Twin tanks likewise allow you to dive deeper and longer, and is probably the main reason why people use them. Same with a rebreather.

Skills and protocol for OC and RB diving are quite different.
Some OC skills have to be untrained and replaced with RB skills. Much like a diver that comes out of normal, recreational OW/AOW dive training and wants to learn how to dive in and out of a cave. New equipment, new skills, new risks to deal with.

Hence when you switch from OC, no matter what level you are, to RB you're back to being a bloody beginner. The initial traininng and certification with its limits reflects that. The further along you are the harder that is probably to take. That's why many RB divers, especially on CCR, exceed the limits of their RB training by diving in their accustomed OC range.

Have a look at the fatalities that occured on CCRs. Plenty of people diving past their CC limits, diving solo, deeper and/or longer than they should have been as a CC newbie.

I know in Germany, at least on a project level, new divers have made their OW certification on Dräger SCRs. There are two trains of thought on this, one the established people need some previous OC training/experience, the other let's teach them RB diving and state of mind correctly from the beginning. And the latter point of view does make some sense, in any field. For years and years for example Lufthansa would train their pilots entirely, rejecting applicants with any other flying experience, no matter if PPL or military pilots.

You mentioned Tech1 somewhere I believe. Means GUE training, correct?
While I usually disagree with some of the philosophical aspects of DIR, much of it and all the skill aspects (that I can think of) are excellent. Afaik GUE doesn't yet offer the initial OW certification. You probably remember just how different DIR-F was from your rec agency training ... wouldn't it be nice to just skip that crap and learn to do it right from the very beginning?