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

[SoFloDSO]

Until relatively recently, the recommended ascent rate was 60 feet per minute. A few years ago ascent recommendations were changed to 60 feet per minute at deeper depths, slowing to 30 feet per minute starting at 60 feet. The problem is that anyone with an older computer will have a programmed ascent rate or 60 feet per minute. Your newer computer probably has a newer ascent algorithm with a 30 feet per minute ascent rate and possible deep stops as . A slower ascent rate is never wrong. Most divers tend to ascend to fast. And for a dive to 90 feet, a safety stop should always be observed, the longer the better. There is some evidence that coming up to slow from extreme depths (150-200 feet) may cause actual absorption of nitrogen, but not at the depths you were diving. I agree with the earlier post, the other dives were probably low on and dragging you into their issues. The proper response would have been to get them to slow down, monitor your air closely, and be prepared to share air if necessary.

 

[oldschoolto]

Until relatively recently, the recommended ascent rate was 60 feet per minute. A few years ago ascent recommendations were changed to 60 feet per minute at deeper depths, slowing to 30 feet per minute starting at 60 feet. The problem is that anyone with an older computer will have a programmed ascent rate or 60 feet per minute. Your newer computer probably has a newer ascent algorithm with a 30 feet per minute ascent rate and possible deep stops as . A slower ascent rate is never wrong. Most divers tend to ascend to fast. And for a dive to 90 feet, a safety stop should always be observed, the longer the better. There is some evidence that coming up to slow from extreme depths (150-200 feet) may cause actual absorption of nitrogen, but not at the depths you were diving. I agree with the earlier post, the other dives were probably low on and dragging you into their issues. The proper response would have been to get them to slow down, monitor your air closely, and be prepared to share air if necessary.

Did you read the thread... They were not low on air.. The OP was the one with the low air/high air consumption...

Jim...

 

[Patoux01]

Did you read the thread... They were not low on air.. The OP was the one with the low air/high air consumption...

Jim...

Did you get their gauges? I don't recall having seen their air consumption. And 1100 psi is not low on air on ascending... Maybe they just didn't tell it?

I just looked at my old profiles, I did the same thing, 25m, took me less than 20 minutes to get "way too low on air" according to your standards.

 

[boulderjohn]

Did you get their gauges? I don't recall having seen their air consumption. And 1100 psi is not low on air on ascending... Maybe they just didn't tell it?

Unless you are breathing with a SAC rate of 1.25, in which case it is low on air.

 

[oldschoolto]

Do people read the threads or just type what they thinks sounds good??? 194 posts to this thread... Again... She was the one that thumbed the dive after sucking through about 2100 psi in about 12 minutes.... The total dive time was 17 minutes.... So it was about 5 minutes from thumbing the dive to dive end time... She has not posted the dive profile from the computer... That would be a big help in understanding what happened...

We do know that her SAC was in the neighborhood of 1.25 or better... We know it was only her second deep dive and the other divers said they think she was narc'd... We know that very high breathing rates cause a building of CO2 in the blood stream... We know she had dumped all the air from her BC and was having trouble ascending.... We know Nitrogen narcosis can affect divers in the depth she was at.... We know that CO2 adds to the effects of narcosis... We know that slow ascents add to the gas loading of the body....

We know that this dive should have and could have been handled much better...

Jim....

 

[Saltyhawg]

High respiratory rates result in low CO2 not elevated CO2 hence the symptoms of hyperventilation which are induced by low CO2 (unless something different happens under water than happens on the surface). pH of people breathing fast tends to be high due to that low CO2.

 

[timakempton]

I have read this thread with great interest and find myself stunned by some of the stupid comments being made by very experienced divers and well respected members and moderators.

1. In respect to the OP consumption of air during this dive. She clearly says the actions of the other divers caused her to "freak out", your comments about excessive consumption of gases take no account of her increased breathing rate triggered by this panic.

2. We all know that dumping her air was not a good idea and this made the beginning of her ascent difficult. This is something that has been taught incorrectly and she has learned through the experience.

3. The problem here is one of communication. The lesson to learn here is to establish communication with your buddy before a dive during the planning stage. You should have a discussion with a new dive buddy (regardless of their experience level) about communication on the dive. This should include hand signals as some divers do use no standard gestures in their communications.

The people on this dive were all at fault in various ways but the 2 so-called experienced divers were totally irresponsible in their complete lack of communication with the OP.

ALWAYS PLAN THE DIVE AND DIVE THE PLAN, the OP's buddy certainly did not dive the plan, in-fact it sounds like they did not even listen to the plan...

 

[oldschoolto]

High respiratory rates result in low CO2 not elevated CO2 hence the symptoms of hyperventilation which are induced by low CO2 (unless something different happens under water than happens on the surface). pH of people breathing fast tends to be high due to that low CO2.

This is from a private message with doctormike (Medical Moderator) about this thread on scubaBoard...

I wrote...I also think this is very likely and maybe a higher CO2 count from ineffective breathing..

Dr. Mike responded.... I totally agree with you about the CO2, was going to bring that up but didn't want to derail things further. I was going to post Chatterton's article about that - Diving with Stevie Wonder

Jim...

 

[Patoux01]

Unless you are breathing with a SAC rate of 1.25, in which case it is low on air.

Assuming I didn't make a mistake in the calculations, and you didn't either, that's 35l/min. So averaging the first 20meters of ascent, we get 3 minutes at 20meters (from 30 to 10m, 6m/minute). 3*35*3 = 350l, that's ~30 bar (in a s80 tank). Out of the 75 bar she had left, that leaves her with ~40 bars by the time she reaches the safety stop. Now she has ~400l of gas with her, one could safely assume the breathing rate would go down (ease of breathing, stress falling down, ...), but I wont. So she has 400l, with 35*2 per minute, that still leaves 4 minutes of safe gas for a safety stop (that we all know we can skip should it be unsafe to do). It's a close call, but it works out.

I can understand one being worried, but honestly, there's 2 "experienced" divers right in front of her, even I have already been perfectly able to help a buddy that went a bit fast through his air, without ever causing a safety issue that a stressed diver might be. Monitor the gauge, when she gets to 20 bars you get your slate out, write "you're low on air, use my reserve as to not drain your tank" and give one of your regulators, as simple as that. Or even better, notice the difference in their tank pressure and yours, get your slate out, say "don't worry about gas, we'll share a bit at the end, notice me when you hit 50 bar, then I'll give you a regulator". That way the diver is not stressed or surprised. At least that's how I handle it. Obviously I'm staying ready to grab their reg for them and the 2nd one for me should something happen...

 

[chrisch]

.... A slower ascent rate is never wrong. Most divers tend to ascend to fast. And for a dive to 90 feet, a safety stop should always be observed, the longer the better. ....

Oh dear my friend you will get flamed for that