O2 Bottle for Cavern, Cave or Deep OW

[MikadoWu]

You can deco on Air if you want but you must have redundancy first and foremost and gas plan. Evaluate how you will be diving, what type of deco you'll do and get a bottle for that is suggested.

My first 2 Deco Dives was on Air, dive 112 and 114 minutes, but I enjoyed them

 

[PfcAJ]

100% is THE MOST efficient deco gas as it has zero inerts.

100% can be used for treating DCS.

Anything else does not have those two attributes. There are situations where using 50% makes sense (open water deco following short dives to 140-170’, for instance), but that’s not what you’re talking about.

 

[Bowers]

In deep lake/ocean dives the lower percents (50 for example) are more common because you can get on them early giving a buffer for failed back gas. Your buddy is correct that getting on a 50% mix earlier on will give you similar total times as getting on 100% later on. However, do to the up and down profiles of the caves, most florida caves that im familiar with are better suited to a 100% bottle that can be dropped in the beginning and used at the end of dive when the rollercoaster of depth change has come to an end.

 

[MikadoWu]

A few minutes? I remember doing a dive as part of my full cave course. Average depth like 60 feet, but it was 2 hours long. The instructor not thinking that I would be able to do a 2 hour dive (as all our prior dives were in high flow caves like Ginnie) didn't bring his deco bottle. He had 20 minutes of back gas deco, I had 5 minutes on Oxygen. Getting out of the water 15 minutes sooner is worth the $5 in oxygen that it cost (though obviously we got out of the water at the same time after he finished his deco).

Now that being said at the cavern level, you won't need it. Deco is prohibited on all cavern certs, and most first level cave certs. I started bringing my O2 bottle when I was in the intermediate level between the first level and full cave (called Apprentice Plus under the NSS-CDS program). As I was diving to thirds and deco wasn't unusual.

But if you are planning to do AN/DP level dives, having it will often save you money in the long run unless your shop follows typical cave country pricing (ie bottle is $X per day it comes full, and you pay to fill it back at the end of the rental at $Y per cubic foot along with filling it up as needed throughout the rental period).

Thank for all the feedback. Buying an additional AL40 is not going to break me. I am more concerned with ensuring I am learning correctly. My present instructor is my first time with him. I have bounced shops, as I have never felt I have gotten the quality I believe I pay for. I have looked at some deep county country shops, but they are never available when I am.

Most of my diving is probably going to stay wreck diving, with the Oriskany on the plate in April. But I am no longer afraid of cave diving as I was in the past.

 

[Manatee Diver]

Thank for all the feedback. Buying an additional AL40 is not going to break me. I am more concerned with ensuring I am learning correctly. My present instructor is my first time with him. I have bounced shops, as I have never felt I have gotten the quality I believe I pay for. I have looked at some deep county country shops, but they are never available when I am.

I'm not a strict DIR guy, but a good start is to look at what DIR agencies like GUE does. You don't have to follow what they do 100% but it will put you about into the lane of what you should be doing.

 

[MikadoWu]

100% is THE MOST efficient deco gas as it has zero inerts.

100% can be used for treating DCS.

Anything else does not have those two attributes. There are situations where using 50% makes sense (open water deco following short dives to 140-170’, for instance), but that’s not what you’re talking about.

Thank you the information. This is where my buddy and I have deviated in training. He is your short 140-170 diver with no cave. I want and plan to do the 140-170 dives also, but have the opportunity to do the Cavern and possible cave training too.

Short version, I went to instructor for AN/Deco class, he needed 1 more for cavern and gave me a deal. With a option of joining the cave class too, at a deal.

In deep lake/ocean dives the lower percent's (50 for example) are more common because you can get on them early giving a buffer for failed back gas. Your buddy is correct that getting on a 50% mix earlier on will give you similar total times as getting on 100% later on. However, do to the up and down profiles of the caves, most florida caves that im familiar with are better suited to a 100% bottle that can be dropped in the beginning and used at the end of dive when the rollercoaster of depth change has come to an end.

This makes total sense, and fits what I was thinking. Again, am not sure I explained all correctly. Thank you.

 

[helodriver87]

The unfortunate reality is you're just gonna end up with a ton of bottles if you continue to progress down this path. The most efficient plan for you, should you choose to pursue both cave and deeper OW stuff, is a 40 that's dedicated to O2 and an 80 dedicated to 50%. Use the 40 of O2 for your cave dives and the 80 of 50% for your deep OW dives. They pair up really nice on down the road for longer OW bottom times and deeper caves.

 

[happy-diver]

But I am no longer afraid of cave diving as I was in the past.

This is fantastic

 

[rjack321]

Thank you for the feedback. I rather not pass on instructor names, as I may be the idiot not explaining things correctly. We are diving Gennie Springs, Bufford, Paradise Springs, and another north of Gennie I do not remember.

Buford? For AN/DP?

Your instructor is absolutely violating standards taking you below 100ft there and having you in deco. Run away now.

 

[ChuckP]

My first 2 Deco Dives was on Air, dive 112 and 114 minutes, but I enjoyed them

Hopefully you'll learn that isn't the best choice. AN/DP should teach you enough that you can plan square dives or just long dives and plan all your gases accordingly. An Al40 with a dedicated reg is a must really, sure you can rent one but you'll need one every dive. The broader your diving becomes, the more experience you have - you'll figure out what gases work for your dives - 50 and 100 is a great start.