Redundancy Required for Decompression Diving?

[scubadada]

...Part of this for me falls under the currently scary long thread about "lite" deco...

As my very young son used to tell his grandmother, "tell me a story, too scary for you, but not too scary for me"

 

[dumpsterDiver]

Obviously people can dive the way they want and can conduct decompression and deep air dives without any certifications.

My question pertains exclusively to what is being taught as recommended or required when a diver gets technical trading to do deco dives.

That is a disingenuousness and "trick" question???

 

[victorzamora]

DD: My understanding is that all agencies require at least an H-valve for their early tech courses. I know that Cavern can be done in a single tank with an H-valve, and I'm fairly certain most require an h-valve. I believe Tec40 and Intro to Tech courses can be done that way. I could be mistaken, but I think even AN/DP can be done that way.

That builds some redundancy in as a "minimum" for the curriculae (is that the right suffix?), the question then is do you consider that redundancy?

 

[dumpsterDiver]

Thanks. I'm just trying to learn what the standards are. I personally used to use a y valve for deep air solo deco dives without incident, but after a while I just didn't feel right about it and switched out the valves and started to drag a pony around. I had assumed that some level of redundancy was required (by standards) to do deco, but was surprised by some comments which seemed to be in conflict with my assumptions.

I only know about technical diving from reading stuff. Mostly the internet.

 

[tbone1004]

Thanks. I'm just trying to learn what the standards are. I personally used to use a y valve for deep air solo deco dives without incident, but after a while I just didn't feel right about it and switched out the valves and started to drag a pony around. I had assumed that some level of redundancy was required (by standards) to do deco, but was surprised by some comments which seemed to be in conflict with my assumptions.

I only know about technical diving from reading stuff. Mostly the internet.

TDI does allow their AN/DP class to be taught with a single cylinder and does not require an H valve. I don't like it, but they do.

 

[scubadada]

TDI does allow their AN/DP class to be taught with a single cylinder and does not require an H valve. I don't like it, but they do.

But with a minimum redundant/deco cylinder, ?40 cf, correct?

 

[tbone1004]

But with a minimum redundant/deco cylinder, ?40 cf, correct?

sort of. So the deco cylinder needs to be sized appropriately, no minimum required. Advanced Nitrox requires a secondary attached to the backgas or a minimum of 13cf pony bottle. Deco bottles need to be sized appropriately but most use a 30cf or 40cf bottle.

this is NOT redundancy because the deco bottles can't be used at depth, they are not pony bottles or a replacement for redundant air systems. Yes your backgas is your redundant air source for decompression, but that's a different discussion

 

[Lorenzoid]

I only know about technical diving from reading stuff. Mostly the internet.

Judging from some of your posts, you have learned from the school of hard knocks how to survive what I would call some aggressive diving. Don't call it "technical" if you don't want to.

 

[scubadada]

Judging from some of your posts, you have learned from the school of hard knocks how to survive what I would call some aggressive diving. Don't call it "technical" if you don't want to.

The school of hard knocks can also be interpreted as extensive experience and careful forays into the forbidden zone. I appear to have a few more dives than you, DD, many more.

 

[Lorenzoid]

The school of hard knocks can also be interpreted as extensive experience and careful forays into the forbidden zone. I appear to have a few more dives than you, DD, many more.

Yes, that's exactly what I meant. Sounds like you are interpreting my post as critical of DD. Not at all.