Buddies kept grabbing/pulling me to ascend faster than computer said was safe

[boulderjohn]

Of course it is possible to ascend too slowly from half an hour at 150 feet or more, but from 90 foot with no decompression? Really? I mean how slow does one have to go to get on gassing at that depth?

So you recognize that at 150 feet or more, when you start to ascend, the faster tissues that have taken on a greater nitrogen pressure than the gas being breathed will begin to off-gas, while the slower tissues that have less nitrogen pressure than the gas being breathed will continue to on-gas. You further recognize that if you ascend too slowly, those faster tissues will approach equilibrium and slow down or even stop their off-gassing, while the slower tissues continue to on-gas. You recognize that at depths greater than 150 feet, this could be a problem.

But you argue that this does not occur at lesser depths. Can you explain the physics behind this? What happens on a dive at 90 feet that makes it so that all tissues are off-gassing, no matter how slow the rate of ascent? Can you explain why ascending at, say, 1 foot per minute from 90 feet would result in more off-gassing than on-gassing?

 

[chrisch]

.....when I surfaced I had between 626-726 psi so I would have had time to take a slower ascent. .....So when I got to 1100 psi I told him we needed to head up.
....my computer started beeping at me. So I slowed down within my computers range. He then grabbed my hand and started pulling me up. It really freaked my out because my computer beeped and said "ascent too fast". .....

...... Three, I say again... THREE other divers were concerned that she was getting herself in trouble and had sucked through her tank way to fast... All 3 were trying to get her to move up the water column faster... Young divers need to learn how to deal with Narcoses.. ...

I've been back and re-read the OP. I have snipped it above. I don't care if it were three or three hundred that doesn't make them right.

The OP started up at 1100psi - 70 odd bar. Surfaced with at least 40bar. So the ascent was 30 bar. Over 30m - that doesn't look too bad to me. Narcosis isn't relevant - you don't "learn to deal with it" you remove it. Any remote possibility narcosis will have gone by half way back up. Maybe the three other so-called "experienced" divers were narced? The wanabee tec diver perhaps?

Is it possible the person swimming in the wrong direction was low on gas? There are so many possibilities to this story that we simply don't know. It isn't a good idea to suggest that the OP listens to people whose behaviour is at best questionable. Is it possible - for example - the OP had started to sink again at some point and this is the reason, not the "too slow an ascent" nonsense? If so why didn't these alleged "experienced" divers say so?

Whatever the complete truth the OP was frightened by the other divers' actions. That is not a good place to be. That is why people stop diving and take up golf. I think it is important to support and help new divers and to look at this as a learning opportunity. So far the only learning I can see is don't dive with people that don't care about you.

---------- Post added April 29th, 2015 at 04:06 PM ----------

So you recognize that at 150 feet or more, when you start to ascend, the faster tissues that have taken on a greater nitrogen pressure than the gas being breathed will begin to off-gas, while the slower tissues that have less nitrogen pressure than the gas being breathed will continue to on-gas. You further recognize that if ascend slowly, those faster tissues will approach equilibrium and slow down or even stop their off-gassing, while the slower tissues continue to on-gas. You recognize that at depths greater than 150 feet, this could be a problem.

But you argue that this does not occur at lesser depths. Can you explain the physics behind this? What happens on a dive at 90 feet that makes it so that all tissues are off-gassing, no matter how slow the rate of ascent? Can you explain why ascending at, say, 1 foot per minute from 90 feet would result in more off-gassing than on-gassing?

You are trying to apply a high level academic principle to a specific incident where it is irrelevant. I don't understand the purpose to this. The dive was to 30m - and we are all agreed it was a short dive. Are you trying to suggest that a super slow ascent from that depth is somehow going to add a decompression penalty to the dive? The OP is AOW. Why are you banging on about something that has no relevance to the dive whatsoever? Decompression theory is contentious. There are no such thing as tissue pressure groups, the theory of tissue half times is actually only an hypothesis. Modern decompression theory is simply a mathematical model of what most people think the body behaves like under hyperbaric conditions. Move the debate about this to Tek to Tek and we can delve into it a bit deeper (forgive the unintended pun).

The OP followed the computer's recommendations to ascend at a given rate. The other divers bullied her beyond that rate. I find that inexcusable without a very very good reason. No good reason is given. A number of posters THINK that it MIGHT be the low gas situation. Perhaps it was - it is one possible explanation. A lot of people have not moved on from 50 bar back on the boat. Another - perfectly plausible - explanation is they were a bunch of jerks. I wasn't there, I don't know. I do know that the manufacturers of dive computers will employ the best possible and latest thinking about decompression theory into their products. Assuming (and I can again only assume) the computer was working properly then the OP was ascending correctly and if she required assistance it was simply to be given more gas. Freaking someone out and pushing them to violate the computer's maximum ascent rate is wrong however you look at it.

 

[Basking Ridge Diver]

On a slightly different tangent - this thread has finally piqued my interest enough to finally order Deco for Divers. I know sometimes these threads wonder and some folks may not realize that some of us actually read them and learn something or want to learn more. So to those that give advise and wonder if anybody reads your words - some of us do and we thank you for repeating your words on multiple threads. Sometimes we just need to be ready to listen and act.

 

[oldschoolto]

"Narcosis isn't relevant - you don't "learn to deal with it" you remove it."

Would "LOVE" to hear how you do that , Without going tri-mix.... Some people start showing signs of narcosis at 60'... And EVERY dive is a DECO dive....

Three divers are "WRONG" and a 20+ dive wonder that doesn't know how to use a BC and sucked through a tank in 15 minutes is right...

If you take into account her being narc'd... The whole thing makes sense... I'll put my money on it...

Jim...

And some " DIVERS " should take up GOLF or BOWLING.... It would be safer for them....

 

[doctormike]

Some people start [-]showing signs of[/-] reporting that they have narcosis at 60'

Three divers are "WRONG" and a 20+ dive wonder that doesn't know how to use a BC and sucked through a tank in 15 minutes is right...

If you take into account her being narc'd... The whole thing makes sense... I'll put my money on it...

Wow, not a lot of love for the OP here. A new diver has a bad experience, writes it up here for us, and because of her SAC of 1.0 people assume that she's an unreliable witness, and the guy in tech training must have saved her life.

I mean, I have no idea what happened there, I only have her side of the story. But that's all we ever have in these forums, and that doesn't mean that we can't discuss it.

It's not a court of law. No one is under deposition here. Based on her report, it does sound like she was pulled up fast by divers who didn't really have a good reason, when she had enough gas to complete an ascent. Don't see why we are assuming things and insulting a new diver (who I guess is still reading this thread) based on unfounded assumptions.

 

[redacted]

You are trying to apply a high level academic principle to a specific incident where it is irrelevant. I don't understand the purpose to this. The dive was to 30m - and we are all agreed it was a short dive. Are you trying to suggest that a super slow ascent from that depth is somehow going to add a decompression penalty to the dive?

Well, of course it could. Are you suggesting it could not???

 

[oldschoolto]

She ( the OP ) was looking for our view on this... we are giving it... Maybe you like this better...

You were man handled by a bunch of old time, no nothing divers that it seems can't even read a compass... You should take as much time as you like to come up... Diving is FUN, FUN , FUN... Don't let a little thing like not knowing how to ascend from 90' bother you... It's over rated... And alway stare at your computer to tell you what to do... It's all you need to do... Now go get your Dive Master card so you can start train the next class of divers...

Jim....

 

[BFRedrocks]

She is a new diver with just under a 100 dives, And her third time going deep....
Jim...

Not to tangent off topic, but I was curious...So your wife has 100 dives and yet has only gone deeper than 60 feet three times? When I first read "new" diver with 100 dives I was thinking that wouldn't necessarily make her new in my book, but if she has 95 dives at less than 60 feet for ~30 minutes/dive, I guess 100 dives like that can provide a much different skill set than say doing 50 dives at 80+ feet for 50 minutes/dive for the same 100 total.

Kinda fits with the earlier comment where someone mentioned that a diver who's been "doing it for 30 years," but only doing a few dives per year, will have much less experience and knowledge (likely) than a 5-year diver who does 50 dives/year in deep, cold, current, etc. So you can't get much from the person who says, "Listen to me...I've been diving for 30 years." FWIW, I still agree that unless you are dropping off the wall uncontrollably (or the other mentioned reasons like unconsciousness), there is no reason for a one diver to put their hands on another diver.

 

[doctormike]

She ( the OP ) was looking for our view on this... we are giving it... Maybe you like this better...

You were man handled by a bunch of old time, no nothing divers that it seems can't even read a compass... You should take as much time as you like to come up... Diving is FUN, FUN , FUN... Don't let a little thing like not knowing how to ascend from 90' bother you... It's over rated... And alway stare at your computer to tell you what to do... It's all you need to do... Now go get your Dive Master card so you can start train the next class of divers...

Jim....

And your view is that she is a worthless newbie, based on your knowledge of what happened. Got it.

 

[redacted]

I still agree that unless you are dropping off the wall uncontrollably (or the other mentioned reasons like unconsciousness), there is no reason for a one diver to put their hands on another diver.

That's it!!! You really can't think of any other reasons???