large air bubble on a deep dive

[Wibble]

I cannot even begin to understand why a potential diver would ask a question like this!

Curiosity? It's a good thing for experienced people to see other's opinions.

 

[rongoodman]

Oh god please don't tell me my question is that bad haha.

It was that bad.

 

[Marie13]

Oh god please don't tell me my question is that bad haha. I enjoy knowing how things work and while I wait for my chance to take a class, my mind wanders and thinks about various scenarios. This seemed like with the depth it would've been something not covered by a basic open water class.

Thank you both for answering/indulging my newbie question.

If you want to know how stuff works, pick up Deco for Divers by Mark Powell, 2015 revised edition.

And, yes, your question was very bad. You think our responses were bad, have a look at the responses to similar on the Dive Talk FB group.

 

[grf88]

I cannot even begin to understand why a potential diver would ask a question like this!

It is called intellectual curiosity, a very positive trait.

 

[Manatee Diver]

It is called intellectual curiosity, a very positive trait.

This. You can wonder about things that you would never do.

There are a lot of things I wonder what would happen, but I would never do to actually find out.

 

[Duke Dive Medicine]

I haven't even taken my rec OW course, but my brain is always going on about what ifs. So here we go... You're on a deep dive, say 600-800 feet. in a cave and you walk out into a dry cavern... what kind of havoc is this going to play on decompression? or say a longer dive at 200-400 feet and then you pop up into air in a cavern... Your body clearly isn't under the same pressure as when in the water. My mind says you'd be in pretty rough shape, but on youtube I'm seeing videos of guys cave diving and coming up into air pockets and chilling for awhile. Same for people using diving bells as deco stops. is there a lot I just haven't learned yet/missed?

You've already gotten the answer from a physics standpoint, but just to expand a little bit: the normal recreational dive limit on compressed air is around 120 feet. With tech diving, usually done with helium/nitrogen/oxygen blends and other gases for decompression, the depth depends on the training, the agency, the decompression algorithm, and the equipment, but for reference, the U.S. Navy depth limitation on standard heliox decompression is 300 feet. Many times on deep commercial or military dives, a diving stage (basically an elevator) with an open-bottom hemisphere is employed as a safety measure (see photo below). As another poster pointed out in answer to your cave question, the pressure of the gas in that hemisphere must be at ambient pressure in order to keep the water out. The same physics applies. Beyond that, saturation diving is usually employed. You'll find stories of civilian tech divers going far deeper than 300 feet but the risks increase with increasing depth.

Please don't let the snarky responses keep you from asking questions. Chances are pretty good that if you had the question, lots of other people did too. The people who are dishing on you for not intuitively knowing the answer to this are doing so to make themselves feel superior. For those folks, kindly keep the sarcasm and look-down-your-nose-ishness out of the diving physiology and medicine forum. As a reminder, this is a learning zone.

Best regards,
DDM

 

[grf88]

Looking at some of your responses I started to think that I was on DecoStop which drove away people looking for information.

 

[ScubaSquatch]

There's nothing wrong with curiosity.

"There's a billion wonderfully nice people on this earth you will never meet, but assholes will go out of their way to shake your hand" - Jim Lindberg

 

[DAJ]

 

[Wibble]

Some impressive play from the right back!