Question about ascent incident

[Leejnd]

Good to hear you were ok, how did the people on the boat react?

Well they didn't actually know about it, since nobody on the boat saw our brief surface. It was the last dive and the boat was preparing to leave, so everyone was involved with that. Only after we'd been on the boat for a while did my buddy and I sit down to do a full de-brief, and then we talked about it with a few folks, but none of them seemed too concerned...which is one of the reasons why I asked if I really was at any health risk.

 

[HowDidIGetIntoThis?]

Were you, by chance, using rental equipment or equipment different from what you were used to? I've been using rental equipment and there is just enough variation in the position of the buttons on some of the inflators that I find it necessary to really concentrate on hitting the right one. It must increase the chances of making an error. And gloves don't make it any easier.

WRT ankle weights, unless your legs are in great condition you'll probably get tired of dragging the weights around pretty quickly. I also found that out the hard way. Too much lead, or in the wrong position, can make diving an awful lot of work.

 

[Storm]

As a rookie who just went through what you;re going through might I suggest a few things?

First your floaty feet, as someone mentioend, could simply be a trim issue. Move your tank back, or down when on dry land, a bit and see if your feet come down a bit.

Secondly, as someone else mentioned, the biggest differences in pressure exist in the first atmoshpere (35 feet or less), and it's here that those unexpected "up elevator" experiences usually happen.

Thirdly, you might want to consider doing a few (as many as it takes) shallow buoyancy dives in the 25 to 30 foot level. My wife and I spent the summer in shallow water working on tim and buoyancy control. I was advised by a DI that if we could get our buoyancy control and trim dialed in at one atmosphere, then we should have little problem at the deeper depths. It seems to have worked for us. Both of us have gotten our buoyancy dialed in, and our trim set pretty well. (I am sure that a Fundies instructor would see it otherwise, but that;s anouther tale)

Also, we took this opportunity to get our gear configuration squared away. One of the advantages of doing all those shallow "skills, buoyancy paractice, and equipment check out dives" is we now know what our weighting is for all of our various exposure suites (7mm, 7mm w 7mm Hooded vest, 5/4 mm, 3mm shortie), and have them logged for future reference.

We also took the time, while on those same dives to practice some more "advanced" or task loaded skills like shooting a DSMB, switch to back up mask, run a navigation line, and of course the basic safety skills.

When I first get certified, last year, I wanted ot go deep and see cools things. It was a bit frustrating, at first, to use this self imposed minimum depth limitation, but in hind sight, it was a very good call and helped us get control of the buoyancy and trim, and our skills are almost at that insticntive level.

 

[Chad Carney]

Some observations:

Shallow water compresses your suit very little, so naturally you are going to be more buoyant in this part of your dive.

After 35 minutes your tank had become pretty light as well.

Females often have more buoyancy in the lower body and need to balance weighting for it.

You said, "I was having some trouble maintaining depth. I tried to vent my BCD, but I guess I didn't realize how inverted I was...I realize now I should have used the vent on the back, but I didn't. I thought I'd raised the deflation hose high enough..."

There is no way to hold the vent hose high enough if you're floating feet up. You were likely already rising at this point. I disagree about using the rear dump in this case as a new diver. You need to realize your body position is the problem. Rolling over, looking up and deflating your BC with the deflate hose is your best method to solve the uncontrolled ascent. Another secondary suggestion would be to kick your fins, powering down until you feel some compression.

I've seen way too many novice divers attempting to use rear dump valves as crutches for poor buoyancy control. A good diver never needs them, but might like to play around with them.

I don't think I'd call this case "in water recompression." With it's immediacy and no symptoms present, I'd say it's just a do-over, making the safety stop you missed.

Spend some time in a pool or very shallow water practicing buoyancy control, ascents and descents. Deliberately create your legs floating ascent condition again and fix it this time before you get close to the surface.

It was an opportunity to learn. Use it.

Chad

 

[ItsBruce]

Someone else suggested that, but I SWEAR I knew the difference! I'd been inflating and deflating it without trouble up until then...I agree that it would seem the most likely explanation, but I shudder to think I would have made such a boneheaded error!

LeeAnne

First, I'm glad to hear you are ok. Second, I'm glad to hear you did not panic. And, that's good enough to get you into the "I'd dive with you" category. Third, in an uncontrolled assent, breathing rapidly is actually a good thing as it minimizes the risk of a lung expansion injury.

As to the bubbles and your certainty that you were pushing the right button, a number of years ago, there were a rash of incidents in which Audi automobiles allegedly lurched forward and caused serious injuries to those in front of them. In each instance the drivers swore they were depressing the brake and that they knew the difference. I recall that one asserted that as the car was crushing his/her (I don't recall which) child, he/she pressed the brake harder, but the car pushed forward even harder. Forensics subsequently showed, if I recall correctly, that (1) there was nothing wrong with the brakes, and (2) under no circumstances could the engine power exceed the power of the brakes to keep the car from moving.

 

[TheRedHead]

I've seen way too many novice divers attempting to use rear dump valves as crutches for poor buoyancy control. A good diver never needs them, but might like to play around with them.

C'mon, Chad. We all have to vent at some point during the dive. Either you vent through the inflator hose or vent through the rear dump valve. The trick is not to wait until you begin to cork before venting.

 

[Leejnd]

Were you, by chance, using rental equipment or equipment different from what you were used to? I've been using rental equipment and there is just enough variation in the position of the buttons on some of the inflators that I find it necessary to really concentrate on hitting the right one. It must increase the chances of making an error. And gloves don't make it any easier.

Yes, in fact it WAS rental equipment...and on top of that, it was the first time I'd been diving wearing gloves. We didn't wear gloves on our four OW dives in the Caribbean. So that probably did have something to do with my somehow pressing the inflate button. Something else for me to focus on as I practice.

I don't think I'd call this case "in water recompression." With it's immediacy and no symptoms present, I'd say it's just a do-over, making the safety stop you missed.

Good point -- that may very well be what he was thinking...I haven't really talked in detail about this with him.

It was an opportunity to learn. Use it.

Yes...that's precisely what I'm doing with this thread.

Thirdly, you might want to consider doing a few (as many as it takes) shallow buoyancy dives in the 25 to 30 foot level. My wife and I spent the summer in shallow water working on tim and buoyancy control.

Good advice. I saw quite a few cool things on my Catalina dives, and I plan on my next several dives to be beach dives, so I'll be sure to forgoe all the searching for cool stuff and spend more time on practicing my skills. One thing that I definitely got out of this experience was infinitely more respect for the risks involved, and the importance of mastering the necessary skills!

First, I'm glad to hear you are ok. Second, I'm glad to hear you did not panic. And, that's good enough to get you into the "I'd dive with you" category.

Garsh thanks! I must admit to being rather pleased myself. Even though we might think we know how we'll react in various situations, it's hard to really know until it happens. It's given me a level of confidence I didn't have before that if something should occur, I'll be able to manage the fear and do what needs to be done.

Third, in an uncontrolled assent, breathing rapidly is actually a good thing as it minimizes the risk of a lung expansion injury.

I remember thinking, the moment that I realized I was in an uncontrolled ascent, to NOT hold my breath! One question...should I have been exhaling the whole time? I just kept breathing, but I wondered later if I should have been exhaling instead.

As to the bubbles and your certainty that you were pushing the right button...

Yeah well, I guess I've already had to come to the painful conclusion that I did in fact do the amazingly boneheaded move of inadvertantly pressing both the inflation and deflation buttons at the same time. :11doh: I'd rather NOT believe that, but it's the only explanation for all the bubbles. Ah well, that's what a learning experience is all about...trust me that I will NOT make that mistake again!

LeeAnne

 

[DaytonaDave]

Lee...

Most of your questions seem to be answered... but I have one. What kind of fins were you using? I know that some are neutral, some are slight positive, and others are negatively buoyant. When I bought my fins, I noticed that ScubaPro stated that certain colors are neutral and some are negative. Personally, I prefer the more negatively buoyant fin like my Jets. The fin type could amplify your trim issues.

Just a thought.

Dave

 

[EvaL]

Hi,
From my perspective, you did a good de-brief and post-dive analysis. By doing so, it shows you are a learning diver and want to know how to prevent this from happening in future. Good analysis and recommendations from several people here - it might be helpful to go over them mentally so you'd know how to respond if something similar happens again. Just want to add that in an out-of-control ascent, it might be good practice to:
1. Use the dump valves or the pull-dump valve of your inflator hose instead of pressing the purge button on the inflator hose. Those valves let air out much faster and will slow your ascent quicker. When you get your own BCD, you'll be more familiar with their location and can reach them instinctively after several dives.
2. Spread your arms and legs (like a skydiver) to create more drag. I think this is secondary to dumping the air in your BCD as it'll only slow your ascent, not stop it.
3. Don't hold your breath, better still, breathe out while you ascend so you don't hurt your lungs.
4. If it is a malfunctioning inflator that keeps pumping air into your BCD, be prepared to disconnect it from the inflator hose. I know this didn't happen, but you might want to be aware of the possibility of it occurring.
I agree with trying ankle weights. My buddy has been using them for years to keep her legs down.
I think you're a much better diver after this incident. Dive safely.

 

[jpcpat]

LEEJND - Thanks for the thread. I did my O/W in a 7mil F/J, and turned my fin pivot into an unplanned ascent through an inflate/deflate confusion. These things happen. It's a learning experience that we all go through. As long as you keep breathing, other problems are usually manageable, especially at depths like that.

Now, it seems most likely to all that you hit both buttons at once and the overpressure valves opening caused the rush of bubbles. Depending on how far from horizontal you were, it's possible you pulled the hose and activated the pull dump. If you were moving quickly already, you can't dump air fast enough to slow yourself.

BTW, In a heavy wetsuit, bouyancy changes fast enough that I warn students about the spaceship at 15 ft waiting to suck them right to the top if they don't anticipate the change.