Question When do we speak of technical diving ?

[johndiver999]

Just wanted to let you know I completely botched the calculation by taking panic into account twice, making it overly conservative. The standard estimate for SAC rate should be 20L/min. I didn't pick up on my error at first since I never dive single tanks. The correct numbers should be:

20m = 613L = 60bar in AL80
40m = 1720L = 160bar in AL80

This is with the metric calculation, the imperial version might give very slightly different numbers, but nothing significant.

And I stand by the comment that a single AL80 to 40m is an interesting choice with these gas requirements.

Still seems ridiculous, but I'm not going to argue about it. I just knew I could make it from 130 to the surface with a full tank!

 

[steinbil]

Still seems ridiculous, but I'm not going to argue about it. I just knew I could make it from 130 to the surface with a full tank!

Of course you can make it back with less gas. The question is, can you comfortably deal with an issue at 40m at the worst point in the dive (with the most nitrogen loading and lowest on gas), share gas with a possibly panicked diver, and then make a slow and controlled ascent all the way to the surface while sharing gas. I'm happy being on the conservative end of that situation, knowing I don't have to worry about running out of air or make a fast ascent from depth.

 

[johndiver999]

Of course you can make it back with less gas. The question is, can you comfortably deal with an issue at 40m at the worst point in the dive (with the most nitrogen loading and lowest on gas), share gas with a possibly panicked diver, and then make a slow and controlled ascent all the way to the surface while sharing gas. I'm happy being on the conservative end of that situation, knowing I don't have to worry about running out of air or make a fast ascent from depth.

I agree, having more gas than you need makes things much simpler, safer and less stressful. I’ve had to share air with a diver once, for real from a depth of just 80 or 90 and I was amazed and horrified how much gas he sucked down during the ascent. Even if you are calm and collected during an emergency, you are not in control of the buddy - no matter how good you think you are.

 

[Blackcrusader]

Of course you can make it back with less gas. The question is, can you comfortably deal with an issue at 40m at the worst point in the dive (with the most nitrogen loading and lowest on gas), share gas with a possibly panicked diver, and then make a slow and controlled ascent all the way to the surface while sharing gas. I'm happy being on the conservative end of that situation, knowing I don't have to worry about running out of air or make a fast ascent from depth.

Only once in my life yes.
I have had to with a dive buddy who is also BSAC Dive Leader trained deco diver. I wrote about it on the forum. He wasn't panicked in that he was trying to get to the surface. We avoided a fast ascent. Were weren't on a planned deco dive either. Good thing were were both deco trained by the same agency though.

 

[Tigerpaw]

What about Ice Diving? There's no overhead.

 

[Cthippo]

What about Ice Diving? There's no overhead.

I thought the ice was the overhead, as in you can only reach the surface at the hole you entered through.

 

[Capt Jim Wyatt]

I thought the ice was the overhead,

It is.

 

[Tigerpaw]

It is.

Sooooo, is Ice considered technical or is it a grey area?

 

[Capt Jim Wyatt]

is Ice considered technical

I would consider it tech because there is an overhead. The definition of "tech" has long been debated.

 

[broncobowsher]

It's not "open water"