Single Cylinder vs. Doubles

[boomx5]

I wondering how deep you will dive with a single cylinder. And at what point do you find it necessary to use doubles. If you could, please include the variables (cylinder size, gas mixture etc.).

 

[detroit diver]

I'll take an AL80 single to 120, but I won't stay too long! And I'll make sure that I've got a competent buddy.

Saba is a perfect example. The pinnacles start at around 90 and go much deeper. I was diving 32 percent Nitrox and took it to the max (for me 1.4 PP02) at 111 fsw.

I don't dive singles anymore locally. I like the extra gas for safety on shallower dives, and need the extra gas on the deeper stuff.

 

[roakey]

There's one dive I did with twin AL80s. About an hour long total, it took us half an hour to reach the surface from when we turned the dive.

Our maximum depth was sixteen feet and I would have never done it with a single, that'd be way too risky.

Your question is more than a bit wide open.

Roak

 

[AquaTec]

single or dbl is a simple matter of how much gas you need to safely perform your objective. if it can be done on a single tank then that is fine if not well dbles become needed.

 

[builderbloke]

i did a 41 meter dive on a single 18L steel tank for 31 min given the choice though i would have done the dive with twin 12 and got more bottom time but i was on holiday and the dive shop out in cyprus didnt have any twins for hire back in the uk i wont go past 25 meters without a twinset as the cold water and poor viz increse your air consumtion quiet a lot

 

[Goeduck]

roakey once bubbled...
There's one dive I did with twin AL80s. About an hour long total, it took us half an hour to reach the surface from when we turned the dive.

Our maximum depth was sixteen feet and I would have never done it with a single, that'd be way too risky.

Your question is more than a bit wide open.

Roak

I'm cornfused, maximum depth/sixteen feet???????

 

[detroit diver]

It's got to be a cave, yes?

 

[roakey]

detroit diver once bubbled...
It's got to be a cave, yes?

Ladies and gentlemen, we have a winner!

Depth is not the issue, overhead is. And overhead can either be physical, as in a cave or physiological, as in requiring decompression. Any time you are in an overhead situation where the surface is not an available sanctuary, you need redundancy in order to buy the time to reach the surface safely. That’s where doubles come in.

Roak

 

[detroit diver]

Do I get my pick of anything off the top shelf??=-)

 

[Soggy]

roakey once bubbled...
Our maximum depth was sixteen feet and I would have never done it with a single, that'd be way too risky.

Huh?

EDIT: Sorry...should read the rest of the post before I ask stupid questions.