Rebreather vs. doubles and gear

[mbeerski]

Hello,
I'm new to the post but not to diving. I have been diving recreational for many years and I'm considering starting technical training. I did not win the lottery so I am considering either buying all the technical gear i.e. doubles, backplate, 2 regs etc. OR a rebreather. So basically about $4K vs. $8K. Have any of you started technical diving or would recommend technical diving with a rebreather? Is there enough redundancy in a rebreather to feel comfortable at 300 feet?

 

[jerrynuss]

Hello,
I'm new to the post but not to diving. I have been diving recreational for many years and I'm considering starting technical training. I did not win the lottery so I am considering either buying all the technical gear i.e. doubles, backplate, 2 regs etc. OR a rebreather. So basically about $4K vs. $8K. Have any of you started technical diving or would recommend technical diving with a rebreather? Is there enough redundancy in a rebreather to feel comfortable at 300 feet?

Without getting into the different types of rebreathers I'll address the question of redundancy and inquire about the type of technical diving you are interested in pursueing.

In a word "No" you will not have redundancy in the rebreather for an incident like a flood of the loop or some other type of critical incident. The common way to address this is to carry the open circuit equipment and gas to be able to handle the worst possible scenario. That is my approach.

Since you are getting into technical diving what are your interests? What are your expectations? What are your goals? What is your budget? Open circuit is the least expensive way to get into technical diving. personally I prefer sidemount for carrying the gas cylinders as opposed to backmount. A lot of technical diving can be done in open circuit and a person can build up their diving resume and experience. A rebreather is obviously much more efficient with gas consumption and can eventually save money when it come to helium. Since you are just wanting to get into technical diving I assume you do not have any experience with helium based mixed gases. It can get expensive if a person is doing a lot of oc diving. Anyway you will want to budget training into your plan. A new rebreather that is capable of "technical" diving can be expensive and so is the training. There is also upkeep and a great attention to detail. So there is still expense and discipline involved.

The way I would explore rebreathers is take a rebreather training course for a nitrox gas mix and rent the rebreather during the course with the option to buy. The way I would approach OC would be to take a cavern through full cave course and get full cave certified.

Read as much as possible and seek out divers doing this type of diving and ask a lot of questions about what works for them.

Best Wishes,
Jerry Nuss

 

[Inst. Dean]

I've been diving my double for 2 years now and love it.
I've been approached by a lot of people about trying a rebreather but have been very reluctant. Especially since I do mostly wreck diving, I would rather have my backup if something were to go wrong inside the wreck.
I guess it's like the previous post said, you have to try it and see what you like and see what works best for the type of diving that you will be doing.

Be safe in whatever you do.

 

[padiscubapro]

I've been diving my double for 2 years now and love it.
I've been approached by a lot of people about trying a rebreather but have been very reluctant. Especially since I do mostly wreck diving, I would rather have my backup if something were to go wrong inside the wreck.
I guess it's like the previous post said, you have to try it and see what you like and see what works best for the type of diving that you will be doing.

Be safe in whatever you do.

I have had my share of both Oc and CCR, when it comes to the SH** hitting the fan in most cases I rather be on my CCR other than a total loop failure which is highly uncommn, the RB gives you more ways to get yourself out of trouble, but a reasonable amount of OC gas has to be carried.

If I was inside a wreck or cave and something went wrong I definately would prefer to be on a rebreather.. time is taken out of the equation in many cases, where as oc its a ticking bomb.. I HAVE been inside wrecks and have had lines cut and collapses, On a CCR I know I have plenty of time to find a solution where as on OC, each breath brings me potentially closer to death.

Many of the dives I do are either impossible on OC or would have an unacceptable level of risk. I rather train someone with a reasonable amount of experience than a heavily seasoned technical OC diver.. Its much easier to break bad habits.

It is quite easy for a good CCR instructor to take a wannabe tech diver through all the necessary training without having to resort to basic technical OC diving.. and in the end you get a diver who thinks like a RB diver not someone who will fall back on OC experience and probably get hurt.

 

[Curt Bowen]

I have had my share of both Oc and CCR, when it comes to the SH** hitting the fan in most cases I rather be on my CCR other than a total loop failure which is highly uncommn, the RB gives you more ways to get yourself out of trouble, but a reasonable amount of OC gas has to be carried.

If I was inside a wreck or cave and something went wrong I definately would prefer to be on a rebreather.. time is taken out of the equation in many cases, where as oc its a ticking bomb.. I HAVE been inside wrecks and have had lines cut and collapses, On a CCR I know I have plenty of time to find a solution where as on OC, each breath brings me potentially closer to death.

Many of the dives I do are either impossible on OC or would have an unacceptable level of risk. I rather train someone with a reasonable amount of experience than a heavily seasoned technical OC diver.. Its much easier to break bad habits.

It is quite easy for a good CCR instructor to take a wannabe tech diver through all the necessary training without having to resort to basic technical OC diving.. and in the end you get a diver who thinks like a RB diver not someone who will fall back on OC experience and probably get hurt.

I agree, I have been OC technical diving for around 16 years with thousands of dives between 130 & 500 feet.

Recently, I purchased a CCR (Megalodon Rebreather) and with the proper training feel that CCR's offers the tech diver more options for escape than OC ever did.

Of course proper OC bailout gas is need for every dive. But if it is not used, its good for the next dive, then the next, so on and so on....

 

[mbeerski]

That's some great info! Any CCR rebreathers you would recommend to get started... something that will not completley break the bank? I want to eventually do some wreck dives up to 300FT.

 

[chrisch]

Great info - cheers. I too have been looking at this problem as to increasing my depth capabilities. My wife/buddy is put off twins by the weight issue.

Maybe in future we would look at RB technology.

Can I ask what OC backup do most people carry for say a 150fsw 20min BT dive?

Chris

 

[padiscubapro]

Great info - cheers. I too have been looking at this problem as to increasing my depth capabilities. My wife/buddy is put off twins by the weight issue.

Maybe in future we would look at RB technology.

Can I ask what OC backup do most people carry for say a 150fsw 20min BT dive?

Chris

Your ultimate bailout really depends on your RMV, and team planning, but on most dives (up to about 1 - 1.5 hrs deco) I carry 1 40 cuft bottle of bottom breathable gas and 1 bottle of 50% for deco, when I am with students I carry larger bottles. I am so used to carrying them I dont realize they are there..

for a 150ft dive I could easily get away with a single bottle of 25% (I would probably carry 36% unless I knew I had to stay at depth swimming otherwise I would have no problem switching to 36% at 150 if necessary (just under a 2.0 po2))
running a +2 on vplanner using 36% would require about 34 minutes of deco (less if you go back on the loop at 20 fsw and run as an oxygen rebreather)

There are alot of ascpects to CCR bailout planning and the above should not be used as a guidleine because I say so (there are reasons and accepted risks behind every choice), various bailout scenarios have specific procedures and reasons and should be taught as part of your decompression planning.

 

[chrisch]

Unscientific I know but I looked at a profile on V Planner as suggested and I reckon at 150fsw for 20 mins I can bail out on EAN32 with 10L (@232 bar) with a margin of safety, based on 21/30 Tx.

Ok you have whetted my appetite - looking for a rebreather try dive now to learn the real facts...

Thanks again.

Chris