55 replies to this topic

[finGrabber]

Is it better to learn deep diving on open curcuit, aka scuba, or on a rebreather?

Ok, to further clarify...I want to dive deep, deeper than recreational limits

so, how should I do this?

Should I learn Advanced Nitrox, Extended Range, and any of the various trimix courses and then switch to a rebreather?

or should I take a rebreather class and then learn the really deep diving aspect?

[6Gill]

Wellllllll....there is no right answer to that one.Generally everyone I know has done the OC trimix,deco ect before investing in CCR.I know one person who went from OW to CCR(but he worked for a CCR manufacture)
My personal opinion is that having a background in OC diving will make you a better CCR diver,not so much in the skill sets like bouancy(there are differences) but in the attention to detail,you'll have a good grasp on the laws(Boyl's,Charles' ect),dive planning and teamwork to name a few.

[Diverbrian]

Is it better to learn deep diving on open curcuit, aka scuba, or on a rebreather?

Ok, to further clarify...I want to dive deep, deeper than recreational limits

so, how should I do this?

Should I learn Advanced Nitrox, Extended Range, and any of the various trimix courses and then switch to a rebreather?

or should I take a rebreather class and then learn the really deep diving aspect?

I'll be watching this with you. I have done everything through Normoxic Trimix on open circuit. I am flirting with learning a rebreather well BEFORE I go to the full/advanced trimix courses. But, I am still not sure if this is a great idea myself.

[6Gill]

[I'll be watching this with you. I have done everything through Normoxic Trimix on open circuit. I am flirting with learning a rebreather well BEFORE I go to the full/advanced trimix courses. But, I am still not sure if this is a great idea myself.

If only time and money wasn't an object then these choices wouldn't require much effort.

[PerroneFord]

I think I'd want to spend quite a lot of time shallow on CCR before worring about putting in a hypoxic mix and going deep.

I think learning OC deep is the way to go personally. Basics like deco, gas planning, team diving, learning how to bail, etc. CCRs have a lot of advantages, but simplicity is NOT one of them.

[ScubaDadMiami]

Not to be contrary for the sake of being contrary, I am now of the opinion that, if I could have done so, I would have just gone closed circuit from the beginning. I think that the reason most people have started on open circuit initially is because CCRs were just not widespread in their use until recently. Open circuit was much less expensive and has been widely available for a long time in comparison to CCR units. So, I think that this is why most people diving CCRs started on open circuit. I don't think it is because it is better to start out on open circuit before going closed.

I liken CCR diving to the difference between flying an airplane and flying a helicopter. (I am not a pilot of either. However, I think there are other analogies like perhaps cars versus motorcycles, etc.) Both pilots understand the same principles of aerodynamics and the like. However, someone that is used to flying a plane would not likely be able to get into a helicopter and hover three feet off the ground right off the bat. On the other hand, I am guessing that one can take helicopter lessons without first becoming a standard airplane pilot. (Again, if I am incorrect, I am only trying to make an analogy here.)

No doubt about it, there will be a lot to learn if you new to diving and are starting out on CCR from the beginning. In fact, there will be a lot more to learn than if you started with some form of scuba before. However, you will also not have to "unlearn" some of the things you had done on open circuit (especially buoyancy) if you start off right away with CCR.

If I were just getting into the sport and the opportunity were open to me, I would go CCR from the start unless finances dictated otherwise.

[seafox]

Not to be contrary for the sake of being contrary, I am now of the opinion that, if I could have done so, I would have just gone closed circuit from the beginning. I think that the reason most people have started on open circuit initially is because CCRs were just not widespread in their use until recently. Open circuit was much less expensive and has been widely available for a long time in comparison to CCR units. So, I think that this is why most people diving CCRs started on open circuit. I don't think it is because it is better to start out on open circuit before going closed.

I liken CCR diving to the difference between flying an airplane and flying a helicopter. (I am not a pilot of either. However, I think there are other analogies like perhaps cars versus motorcycles, etc.) Both pilots understand the same principles of aerodynamics and the like. However, someone that is used to flying a plane would not likely be able to get into a helicopter and hover three feet off the ground right off the bat. On the other hand, I am guessing that one can take helicopter lessons without first becoming a standard airplane pilot. (Again, if I am incorrect, I am only trying to make an analogy here.)

No doubt about it, there will be a lot to learn if you new to diving and are starting out on CCR from the beginning. In fact, there will be a lot more to learn than if you started with some form of scuba before. However, you will also not have to "unlearn" some of the things you had done on open circuit (especially buoyancy) if you start off right away with CCR.

If I were just getting into the sport and the opportunity were open to me, I would go CCR from the start unless finances dictated otherwise.

I have a similar opinion.
As in most things in diving, there is no right or wrong anwer.
I do believe though, that some OC experience has benefits in the transition.
Comfort in the water, ease of manipulating equipment, some knowledge of physiology and physics among other things, I think facilitate the transition.
"Too much" OC experience, if there is such a thing, does bring out the so called "bad" habits, that really have no impact on OC diving, but slow down the transition to CCR, as pointed out very well by SDM.
If moving to CCR is in the relatively near future, I would not embark on the tech path on OC.
I would do the basic CCR, build up the necessary hours and experience and then take the advanced courses
ie: normoxic and full Trimix on my CCR.
I don't see any benefits in doing it twice.
Part of the financial justitification for the CCR is not having to pay up for gear and courses and expensive gas on OC to get to the full Trimix platform and then doing it again for CCR.
It doesn't make much sense!

[Desert_Diver]

Kim,

I'm planning on doing 'em all at the same time, ONLY because I don't intend to actually use the Trimix. You really need a bail-out solution with a rebreather, which gets ugly if you suddenly have to go from CC to OC and you're not comfortable with the stage bottles, yet. If I ever get around to diving mixed gas, I'll probably start all over and do the first 30+ dives OC just for the practice.

I'm interested in RBs for the no-bubbles part during photography, not for the bottom-time at extended depths. One of these days I'll find a deep trip that I just gotta do, so I figured I'd take the courses well in advance.

I used to follow a couple of the rebreather forums, I'll dig around and find the links for you.

[seafox]

Kim,

I'm planning on doing 'em all at the same time, ONLY because I don't intend to actually use the Trimix. You really need a bail-out solution with a rebreather, which gets ugly if you suddenly have to go from CC to OC and you're not comfortable with the stage bottles, yet. If I ever get around to diving mixed gas, I'll probably start all over and do the first 30+ dives OC just for the practice.

I'm interested in RBs for the no-bubbles part during photography, not for the bottom-time at extended depths. One of these days I'll find a deep trip that I just gotta do, so I figured I'd take the courses well in advance.

I used to follow a couple of the rebreather forums, I'll dig around and find the links for you.

Try this:

http://www.rebreatherworld.com/

PS: FYI: If you're NOT using mix, you only need one OC bailout bottle.
Some people would argue that you can use your onboard diluent bottle as a bail out.
That's not the way I do it. But it is a viable option.
I ALWAYS sling an OC bail out bottle.
Learning to use a bail out with an RB is not complicated and is learned on the course.

[Desert_Diver]

PS: FYI: If you're NOT using mix, you only need one OC bailout bottle.
Some people would argue that you can use your onboard diluent bottle as a bail out.
That's not the way I do it. But it is a viable option.
I ALWAYS sling an OC bail out bottle.
Learning to use a bail out with an RB is not complicated and is learned on the course.

I'm with you, I'd rather carry an independant bail-out. Using the diluent is fine as long as there's any left, but even a LP malf would empty the smaller bottles used in RBs in short order. The way my gas block was plumbed, I could also switch over to a pure O2 reg for the 20' stop. When I get it back together again, I'll probably keep that feature.

Looking back on my earlier post, swap the 'going from CC to OC' around. I must have had a brain fart.

Ahhh, the joys of getting a little older. You can blithely wave brain farts off as 'advancing senility' and act like there's nothing wrong with it. ;-)

[seafox]

PS: FYI: If you're NOT using mix, you only need one OC bailout bottle.
Some people would argue that you can use your onboard diluent bottle as a bail out.
That's not the way I do it. But it is a viable option.
I ALWAYS sling an OC bail out bottle.
Learning to use a bail out with an RB is not complicated and is learned on the course.

I'm with you, I'd rather carry an independant bail-out. Using the diluent is fine as long as there's any left, but even a LP malf would empty the smaller bottles used in RBs in short order. The way my gas block was plumbed, I could also switch over to a pure O2 reg for the 20' stop. When I get it back together again, I'll probably keep that feature.

Looking back on my earlier post, swap the 'going from CC to OC' around. I must have had a brain fart.

Ahhh, the joys of getting a little older. You can blithely wave brain farts off as 'advancing senility' and act like there's nothing wrong with it. ;-)

Hey Desert Diver, no problem; we're just exchanging ideas.
That's what it's all about and as long as we keep an open mind, and live by " what ever works works", then it's all in fun, and we can learn from each other.
And man, is there a lot to learn! I have beeen diving for 25 years and still learning!
Getting older has nothing to do with it..,,,,,
Think young, stay young
Re pure 02, keep in mind that with a CCR, you don't really need a 100% 02 deco bottle, since you can increase your set point to 1.4 or 1.5, if you believe in doing that.
There are pros and cons to that methodology and if you do, you really needs to watch you CNS.
Generally, there is no right or wrong, it's whatever works for you! :
:

[devilgas]

Huum, I like doing a 3 1/2 hour drift dive in Cozumel, all at about 70-80ft. Come right out of the water with no deco. Thats why I dive, teach and sell closed circuit rebreathers.

As well, I can do 4 days of 200ft plus dives on Heliox, with just 1 20cf mix fill. Compare that to an average of 1 twin set fill per day at about $100 per fill. The math says it all.

[ScubaDadMiami]

I can do 4 days of 200ft plus dives on Heliox, with just 1 20cf mix fill. Compare that to an average of 1 twin set fill per day at about $100 per fill. The math says it all.

Amen!

[Scubatooth]

Devil gas

which CCR do you sell and train divers on ?

would have asked over PM but yours isnt enabled

[peterbj7]

I'm also interested in knowing who "devilgas" is, as I'm only just down the road.

I also agree that starting with CC and doing all your diving CC makes a lot of sense. I know Tom Mount is of the same opinion. But a CCR only makes sense if you're diving pretty frequently and consistently - otherwise you're for ever throwing away part-used adsorbent and buying new. Possibly not too much of an issue if you're in the US or Europe, but a significant concern down here in the styxx.

The key reason for using CC for deep diving, especially in a place like here where helium is incredibly expensive, is the cost of gas if you're diving OC mix. It's easy for the gas cost of a single dive here to exceed $250.