Next step for longer bottom times on deep dives?

[grantctobin]

I'm only rec certified, never took a tech class.

I carry an extra 30cf cylinder for reserve purposes and since I let my main tank get lower than most due to having the reserve in the pony I find most often my NDL limits my bottom time not the gas remaining and I tend to always have plenty left at the end of each dive. I don't think I've ever taken a breath off my pony bottle.

So I've been letting myself get into DECO for up to 5 minutes or even a bit more, and do the necessary 10 foot safety stop for a minute or more (whatever the computer advises).

That gives me more time without the time and expense of the tech classes and any additional gear.

"I'm untrained, with a decompression obligation, with as little as two hundred psi of gas in my primary cylinder [according to post history], and haven't verified that my pony is functional on this dive. I don't need more classes or gear."

 

[gamon]

"I'm untrained, with a decompression obligation, with as little as two hundred psi of gas in my primary cylinder [according to post history], and haven't verified that my pony is functional on this dive. I don't need more classes or gear."

Wrong on 2 counts but hey who needs accuracy when it makes for a dramatic attention getting post.

 

[rolanddiver]

I never said that he should get a rebreather just because he can afford it. If he wants longer bottom times, less deco obligation than the CCR is the way to go. Eventually he would end up diving one anyways, so why not save the time/cost of OC trimix and get the right tool for the job. Before someone asks, yes I have been diving a rebreather in caves since 2007 and I actually built both of them and I'm still alive.

Very Respectfully

Roland

 

[grantctobin]

Wrong on 2 counts but hey who needs accuracy when it makes for a dramatic attention getting post.

I'm only rec certified, never took a tech class.

I let my main tank get lower than most due to having the reserve in the pony

I don't think I've ever taken a breath off my pony bottle.

That gives me more time without the time and expense of the tech classes and any additional gear.

I don’t typically start to ascend with more than 500 psi in my main tank since I’ve got the large reserve in the pony.

Diver A is your typical single tank AL80 diver, returning to the boat with anywhere between 500-750 PSI.

Diver B has an AL80 plus a second completely redundant 30cf tank. Diver B returns to the boat with between 50-100 PSI in the main tank PLUS a completely full 30cf pony bottle.

Diver B has the safety of redundancy throughout the entire dive plus he returns to the boat with more gas than Diver A.

Diver B is in a much safer position and LESS likely to have an OOA situation than your typical Diver A.

I started with a Spare AIr maybe 10-15 years ago, then upgraded to a 19cf pony bottle and now I carry a 30 ct pony bottle.

You say that you always start your ascent with 1000 psi. When carrying a pony bottle I cut my main tank reserves roughly in half, so I'll start to ascend at around 600 psi and maybe have 300 at my safety stop and surface with 50-100 psi.

I've got the reserve in the pony tank so it allows me to draw my main tank gas lower, giving me extra gas on virtually every dive plus the safety of the redundancy of the second independent tank and regulator.

 

[gamon]

Thanks for saving me the trouble of retrieving my old posts to point out your two blatent errors in regard to my posts, in an attempt to create unnecessary drama.

If you're bored, go diving.

 

[flymolo]

I never said that he should get a rebreather just because he can afford it. If he wants longer bottom times, less deco obligation than the CCR is the way to go. Eventually he would end up diving one anyways, so why not save the time/cost of OC trimix and get the right tool for the job. Before someone asks, yes I have been diving a rebreather in caves since 2007 and I actually built both of them and I'm still alive.

Very Respectfully

Roland

I think if you can easily do the same dive on OC a rebreather is not the right tool for the job. It’s a lot harder to get hypoxic, hyperoxic, or hypercapnic on OC than it is on CCR.

Also, at those depths CCR and OC will have very similar decompression obligations,

 

[flymolo]

Thanks for saving me the trouble of retrieving my old posts to point out your two blatent errors in regard to my posts, in an attempt to create unnecessary drama.

If you're bored, go diving.

it seems somewhat irresponsible to suggest someone start doing decompression dives without proper training or equipment

 

[gamon]

it seems somewhat irresponsible to suggest someone start doing decompression dives without proper training or equipment

I'm not suggesting they do it. I'm simply explaining what I do.

 

[flymolo]

I'm not suggesting they do it. I'm simply explaining what I do.

I understand that. However I'm saying that another reader might see your post as confirmation that it's safe and practical.

 

[gamon]

I understand that. However I'm saying that another reader might see your post as confirmation that it's safe and practical.

I don't really consider it to be unsafe and for practical purposes it gives me a few extra minutes of bottom time.