Question about ascent incident

[Leejnd]

Well garsh, thanks for the compliment! This thread has certainly been wonderful for me. And yes it's sometimes hard to accept constructive criticism...for some more than others. But one thing that I've gained from my OW course and subsequent dives is that, unlike other sports and activities that I've pursued, mistakes or problems can be deadly -- and we may only have seconds to avoid death. I do not take this lightly! If I have to listen to a bunch of people telling me I'm a bonehead, hey tell away...it might save my life one day. Anyway, thanks!

 

[Archangel]

Hi Beeloved LeeAnne:

Since I was the team leader and your divebuddy, I am going to weigh-in on what you have courageously written here.

. . . . .On my third dive we'd been down at 45' for about 25 minutes, and had ascended to 25' and poked around in the kelp there for about 10 minutes. But here I found bouyancy to be a bit more challenging. In addition to this, my fins are more bouyant than I was expecting, and at 25' they kept raising up on me when I wasn't moving forward.

. . . actually, our deepest by my computer was 41 fsw at 21 minutes. I decided to do a rolling decompression and took us to 35fsw and then 30 fsw in a leisurely 10 minute fin. I check time/depth/in 30 second increments. We were diving in a three man. . .'er two women and me team. I took the forward position while you two were wing on wing and following. I ascended to 20 fsw while finning and and watched you two following and ascending from 30 fsw. . .as you began having trouble on ascent, I turned and chased you to the surface.

I gentle reminder from basic OW class, the bubble at 71 fsw is compressed 3 times smaller than on the surface. The bubble at 20 fsw is only compressed by a little less than half. There is a gimongously LARGE difference in bubble size from 70 to 60 fsw versus 20 to 10 fsw. This is probably the reason that you had difficulty with your bouyancy as you ascended from 40 to 25 fsw.

. . . . . He immediately took me back down to 15', and checked me out to ensure I wasn't panicking or feeling ill (I was fine). We stayed there for about ten minutes, and then returned to the boat and surfaced. . . . was it of value to immediately descend to 15'? There were some differences of opinion on this -- some on the boat said that it would have made no difference, as any bubbles in my tissues would have already been formed; others said that if we did it quick enough it might have slowed down the development of bubbles.

I instinctively took you back down as I calculated your time in the water to be 35-40 minutes, with an average depth of 35 fsw without a deco/safety stop. So, I took you down to 15 fsw for 5 minutes and we swam around in circles as we were under the boat. I am eager student of technical diving, and it would be bad form to hurt you, and the team, by ignoring the inviolate laws of physics. I found the second guessing discussion that followed on the deck of the boat ridiculous at best, and reckless at worst.

So, here are my questions. First and foremost I'd like to know if I was truly in danger of DCS by having an uncontrolled ascent from 25'. I can tell you that I didn't hold my breath --

Good that you didnt hold your breath. . . . and no. Chances are slim that you would take a DCS hit. Not impossible, but not likely. What you set yourself up for with an uncontrolled ascent is pneumothorax, arterial gas embolism, subcutaneous emphysema, and a host of smaller and even more ominious things (pulmonary shunt). Heck, with this cast of nasty maladies, I would welcome type I DCS.

One thing I will say that I already learned from this incident is that I didn't panic...I knew something was going very wrong, but rather than feel fear (which I recall thinking would be useless!) my mind immediately went to my training, and tried to scroll through what I'd learned. I do hope that's an indication that I'll behave the same way if I encounter an emergency again.

I am so proud of you, I am so humbled by you. I looked into your beautiful hazel eyes for that "deer in the headlights look" and saw joy, fascination, and happiness. Thank you for diving with me, and I would be honored if we could dive together again.

Much warmth,

Tevis

 

[Archangel]

But...why do you descend horizontally? I'm only asking because I'm always trying to improve my diving)

Dear Dawn:

I am reading thru the thread and if this has already been answered, puhleeze forgive me. A bunch of reasons that horizontal ROCKS:

Think streamlining and drag.

Good times to drag. . . . descents (prevents lawn darting), ascents(prevents uncontrolled ascents) cant wait to get LeeAnne in the pool

Horizontal while finning. . . streamlined in the water column, less air consumption, smaller footprint so easier effort cutting thru the water.

. . . . and you look REALLY cool!

Tevis

 

[Robert Phillips]

I would just like to add a comment regarding power inflators: While you may have thought that you were pressing both buttons you were most likely only pressing the inflate while you assumed you were also pressing the deflate button. Most inflators are designed to dump air faster than they will fill your wing. This is to prevent what occurred with your runaway ascent, or if the inflate sticks or IP creep from your regulator 1st stage: It allows you to dump the air directly into the water column instead of into your wing.
This feature is an important item to look for in any perspective BCD you may buy. Some manufacturers pride themselves on the speed of their power inflators to fill their wings. Sound like a good idea?
Congratulations on keeping yourself together during a stressful event. You were in capable hands with my good buddy Tevis!

Robb

 

[Leejnd]

You were in capable hands with my good buddy Tevis!

Yup, he's my new bestest friend!!! :sappy:

Thanks Tevis for clarifying what happened. I haven't even learned how to read the computer I had on my rented equipment, so I sure couldn't have pulled that info out!

I'm looking forward to working with you and developing my skills. I'm definitely hooked!

LeeAnne

 

[Code Monkey]

I had trouble in the SoCal water with my feet wanting to rise above my head until I changed my trim. I have a weight-integrated BC and I used to put some weight in my ditchables and some in the non-ditchables that are near my shoulder. I've now moved my tank down on the strap (the "corner" of the tank is now only an inch or two above the top of the strap) and put most of my weight on a weight belt. That's done a lot to help me be more horizontal in the water.

The butt-dump on your BC is not something a diving course would have told you about because it's a feature that not every BC has. One thing about the butt-dump, though; if you just yank on it to dump air, you'll empty your BC in one fell swoop. Instead, grab the knob by wrapping your forefinger around the string, anchor your thumb to your BC, and rotate your hand, using your thumb as a pivot, slowly away from the butt-dump. That'll give you more control and allow you to dump smaller amounts of air.

We've all been there -- what you're going through is just part of the "initiation". Keep working at it and you'll get better. Good luck!

 

[DirtDart]

Just a suggestion regarding where the bubbles may have come from. If you've got a spare second stage regulator, it may have vented gas if it got turned upside down. I'm a noob too, but something I noticed is that if the regulator is dialed down to be sensitive enough, it doesn't take much to set it off.

 

[TheRedHead]

I would just like to add a comment regarding power inflators: While you may have thought that you were pressing both buttons you were most likely only pressing the inflate while you assumed you were also pressing the deflate button.

Try breathing off the inflator hose while maintaining neutral bouyancy. :shakehead

 

[CJ Waid]

I ascend and decend extremely fast in 30-35 feet of water and I have never felt anything, and I spend a lot of time on the bottom, I burn all of my air out before I even think about surfacing, so it is not a definate thing that you will get sick or anything like that, it is just for safety, because you COULD get sick, but what I have found is that if you can get away with something once, you can probably get away with it twice. I try to avoid times in a row on anything. You are not going to explode, you might MIGHT get a little sick, if you are in good condition, the rules were designed to account for divers of ALL likely physical conditions though, so I wouldn't let anyone scare you, but do be careful, a slow, careful ascent is definately smarter than what I do.

 

[CJ Waid]

And that thing with your fins is just weird. I think you have evil fins. You might want to have an exorcism.