Rebreather or Open Circuit?

[TechBlue]

Dollar for dollar and long run,, OC is the way to go!

We are planning to start exploring the channel between Mallorca and Menorca this year, average depth will be between 100 and 120M I wouldn't even begin to consider trying to do this on OC logistically the amount of gas needed, deco, cost, safety, etc. would make it way more difficult and with the cost of gas over here we'd have to start robbing banks to cover the cost.

I realize that this makes a rebreather the right tool for the job but as we have already covered diving a breather requires specific skill sets that need to be maintained so I use my breather for all my dives.

We will eventually be teaching CCR diving to new divers, I do not quite understand the need to spend time and money for training on OC just to be comfortable if you need to bail as this will be covered in the training. Is rebreather diving for everybody, absolutely not, but please explain the logic that when every newbie diver starts to look at breathers as an option they are jumped on and get told spend more time on OC and hone their skills to get comfortable in the water, if the student has the correct mindset and attitude there is no reason at for them not to start diving a breather whenever they choose even if it is day one.

 

[mania]

But I remain terribly frightened of complacency and human error. Both are insidious and widespread in ALL human activities, and they are what seems to kill rebreather divers.

I may be wrong, but there just don't seem to be quite as many ways for the diver to make a mistake and kill himself on OC.

with my still limited CCR experience I have noticed that many accidents are a result of routine when preparing for the dive. At the very biggining you really prepare the gear very thouroughly. The more you dive the less careful you are. And this really can kill.

But it goes for both - for OC and CCR. The last one can be more dangerous, but at the same time you have more time to fix the problems uw than you have on OC.

Still, despite that my own organisation allows CCR without OC experience I would never reccomend taking CCR class by a person who never dived with OC.

 

[TechBlue]

Still, despite that my own organisation allows CCR without OC experience I would never reccomend taking CCR class by a person who never dived with OC.

Why not?

 

[battles2a5]

Ryan, that's a lovely post.

I see things from the opposite standpoint. After five years and over 900 dives, I'm not terribly frightened about the unexpected dangerous thing happening to me on a dive. But I remain terribly frightened of complacency and human error. Both are insidious and widespread in ALL human activities, and they are what seems to kill rebreather divers.

I may be wrong, but there just don't seem to be quite as many ways for the diver to make a mistake and kill himself on OC.

I think the point I was trying to get w/ OC is that the gear probably won't get you, but the environment can. A silt-out in a deep cave or in a wreck starts the clock ticking immediately on OC. Getting stuck or lost in a cave does the same thing. You have no option but to get out and get out quickly.

Delays on ascent or descent can REALLY throw a wrech in OC gas plans for deep dives. A 2-3 min delay on the bottom or initial ascent can result in major changes to a schedule.

These risks are mitigated for the most part with CCR. If time is the enemy, a CCR is the best tool you can ask for. In a silt-out I can just wait until it clears, or take my time doing a search because I have huge reserves of time on the loop. If I have a delay that causes me to rack up 20 mins more deco, big deal. It's just time. Or I can bump up the set point to compensate. Of course all of these things need to be compensated by an appropriate OC BO plan, but that's a different thread.

All I am saying is that I will gladly accept the additional risks on CCR in order to gain the options and time that CCR provides. As I mentioned in my first post in this thread these arguments don't hold water for your basic recreational dives, but become a compelling argument on bigger dives.

 

[LiteHedded]

That kind of depends on the dives you do. Shallow, short BT sure OC is more economical. Deep, long dives, CCR wins hands down. Looking at gas alone; a deep trimix dive costs about $15-$18 in dil on CCR, on OC BG alone would be in the $90-$140 range.

agreed
and there are dives that simply can't be done safely on OC

 

[Meng_Tze]

I am going to go home now and hug my Meg.

 

[rigdiver]

Dollar for dollar and long run,, OC is the way to go!

So, you are 150' deep in a silt out cave or inside a wreck and off the line. Given a choice of double steel 130's with cave fills OR a CCR what would You choose?

I'll take my CCR ANY day. No doubt.

 

[battles2a5]

So, you are 150' deep in a silt out cave or inside a wreck and off the line. Given a choice of double steel 130's with cave fills OR a CCR what would You choose?

I'll take my CCR ANY day. No doubt.

Amen to that!

 

[LiteHedded]

So, you are 150' deep in a silt out cave or inside a wreck and off the line. Given a choice of double steel 130's with cave fills OR a CCR what would You choose?

I'll take my CCR ANY day. No doubt.

having recently been in that situation I would say open circuit is just fine

*edit* didn't see the off the line part. i try to only get in siltouts while close to the line

 

[rigdiver]

having recently been in that situation I would say open circuit is just fine

*edit* didn't see the off the line part. i try to only get in siltouts while close to the line

Sometimes people upstream "fix" things for you.