Angst: Cavern & Intro Divers with Deco Bottles - why?

[Jax]

You know, a couple of friends of mine, who are tech trained and regularly tech dive, just did the equivalent of Cavern/Intro. They raised what I thought, and still think is a very legitimate question -- what's wrong with taking an O2 bottle and dropping it at 20 feet, and just spending five minutes or so on it at the end of a dive? A lot of the caves in FL are deep and you can be close to NDLs on dives there, and among folks I know who ARE tech trained, it isn't all that unusual to carry some O2 on OW dives that push NDLS, and spend five minutes on it just because we're old and we like being safe. This doesn't mean exceeding Intro/C1 limits at all in terms of the cave dive; it's just a trained person using O2 because they think it is helpful.

THANK YOU! Exactly what I wish to do.

[Kevin Carlisle]

The incident in question was at Peacock 1. I've made probably eighty dives at Peacock 1, including about seven Orange Grove to Peacock 1 Traverses, and I've never taken oxygen in the water there. YOU DON'T NEED IT! I believe the most deco I've had there was three minutes, and that was from the traverse.

If a cavern diver takes a deco cylinder into Peacock 1, I'll bet you a thousand dollars they're regularly breaking rules.

Exactly!! If you don't need it dont take it. Cavern dives are a No deco dive.

[Jax]

So there we have the two camps - One side is me and LCF, the other is Sludge and Kevin. Hmmm.

[Jarviz]

We just passed our GUE Cave1 so being able to use1/3rd of 2/3rds gas for penetration, using 130's, turning the dive when we used 800 psi.
We dove Peacock, Peanut Side ( not sure if thats Peacock 1), we made it to 1600ft, turned the dive when we used 700psi and just made it back just at NDL limits.
Now being on vacation and wanting to do 2 or 3 dives per day, being deco trained, why not leave 02 at 20ft just to be on the safe side??

[JahJahwarrior]

If we are gonna jump on intro divers with AN/DP certs and O2 bottles in the cavern, we should be jumping on full cave divers lacking AN/DP who do any deco at all just as hard.

I'm not convinced there is a parallel between people diving outside of some limits compared to others.

Example, we all jump on people who cave dive without certification, because there is a proven history of lack of cave training, when diving in caves, being correlated to deaths.

However, we don't jump on full cave divers who do deco with AN/DP because there is hardly any evidence showing it is correlated to deaths.

Or am I wrong? How dangerous is it to do deco with a card (DPV without a card, stage without a card, sidemount without a card), compared to cave diving without a card?

[Superlyte27]

So last Sunday me and mpen decided to do A LOT of diving at Peacock. The first thing we did was The Grand Traverse, came back the long way, through Peanut. Total run time with no deco was 87 minutes. She was rushed for time, so we did a very very minor surface interval, just long enough to grab the truck with the tanks in it, back in the water with less than 40 minutes topside. Then we did Peacock to Pothole to Dark Water tunnel to Crossover to mainline and back out to grab our reels we placed on the first dive and the reel we left at the dark water tunnel. Total dive time never hitting deco was 60 minutes. We got out the water, jumped right back in in less than 30 minutes, This time Peaock to Nicholson, to Cisteen, and back. Total dive time 47 minutes. We pulled out of Peacock on our way home before 1pm. WE NEVER ENTERED DECO. We were diving 32%.

It's about task loading. Intro divers shouldn't add more to their plate than what is absolutely necessary. Deco bottles simple aren't necessary at Cavern and Intro level in Peacock.

[JamesK]

Or am I wrong? How dangerous is it to do deco with a card (DPV without a card, stage without a card, sidemount without a card), compared to cave diving without a card?

I personally feel there is a difference in doing something like Cave without certs compared to something like SM/Stage/DPV without a card. IMO these are things that a good mentor can teach you, and a class is not really a necessity due to the complexity of it. Am I saying that these things are not complex? Not at all. I am simply saying that these are things that I feel could be learned through a mentor-ship program, and not a class. That might sound hypocritical, and I even I can see it is slightly, but it is just how I feel.

[RN]

So there we have the two camps - One side is me and LCF, the other is Sludge and Kevin. Hmmm.

I agree with you and Lynne. I see no problem with bringing along an O2 bottle as long as the diver is not planning on exceeding his/her limits of training. If it's just to help flush out the nitrogen, then go for it. I don't agree with intro level divers bringing a stage cylinder with them to extend their penetration by extending their 1/6s of gas volume with the added cylinder. That exceeds training limits and should not be done. If you're just taking a bottle to practice, then practice in OW. There's too much that can be damaged in the cave while you're practicing with that bottle.

[ianr33]

No deco at intro never made much sense to me either. It's pretty easy to hit deco at Little River or JB on a second dive,even diving to intro gas limits. If a diver is deco trained, why not drop an O2 bottle on the way in,especially as dives may be high exertion if the flow is up?

[Greenwood_60]

If I am correct, the dive in question was Cavern divers, with stage bottles, in the breakdown room. Several hundred feet past the cavern zone, and silting it out.