Larger Tanks for deep dives (100ft)

[DaleC]

As a very wise instructor of mine once said, "You can fix bent; you can't fix drowned." I'll take extra gas, any day. In fact, I routinely dive with a lot more tank and a lot more gas than I need for any given dive. It gives me a warm, fuzzy feeling. (It's one place where I'm not into minimalism!)

+2......

 

[DaleC]

What is "recreational penetration"?

Oh Sas... so many images come to mind.
I guess professional penetration must include some form of monetary compensation???

 

[Sas]

Oh Sas... so many images come to mind.
I guess professional pentration must include some form of monetary compensation???

 

[TSandM]

6ths is a common limit for low-level cave certs. I've never heard it discussed for wreck diving before.

 

[Sas]

6ths is a common limit for low-level cave certs. I've never heard it discussed for wreck diving before.

Ah ok, in my low level cave cert I have a linear penetration limit + rule of thirds not sixths.

 

[ianr33]

Sixths applies to cavern and intro cave when diving doubles. Diving a single the limit is 1/3rd.

 

[Sas]

Sixths applies to cavern and intro cave when diving doubles. Diving a single the limit is 1/3rd.

What agency?

 

[adm3745]

What agency?

NACD. It's discussed in order to prevent new divers in an overhead from penetrating to far.

Doubles shouldn't even be discussed. The op wants to do rec deep divin (100-130 ft). A large steel tank and a calculated rock bottom will provide plenty of gas. More than enough to reach all NDL.

100 ft: NDL 25 min = ~80 cft
130 ft: NDL 10 min = ~40 cft

A cylinder that will give you at least 120 cft would be suficient for all no deco deep dives. (Those NDL are for Nitrox and I don't have the tables in front of me).

 

[Sas]

NACD. It's discussed in order to prevent new divers in an overhead from penetrating to far.

Ok then so is there no penetration distance limit? Sorry if this is a bit off topic, just curious about other agencies' qualifications.

Doubles shouldn't even be discussed. The op wants to do rec deep divin (100-130 ft). A large steel tank and a calculated rock bottom will provide plenty of gas. More than enough to reach all NDL.

It's not just about NDL, there is also the redundancy issue when it comes to diving a large single. For me I always had plenty of gas when diving deeper even with a single tank. But I take redundant air below 30m and I take a LOT of gas as more gas can't hurt. I do use redundancy shallower but not always, but deeper than 30m I use twins. Prior to twins I used single + pony and I think if someone does not have any ambition to do go beyond 100-130ft NDL diving, then this is an adequate setup and perhaps more suitable to the OP than twins.

 

[TSandM]

None of the agencies whose limits I'm familiar with (TDI, NAUI, NACD, NSS-CDS, GUE or UTD) has a penetration limit in distance. The penetration limit is set by gas.