Runaway Ascent (Analysis/Lesson Learned)

[Togalive]

Well the other day I had by far my best dive overall All my gear worked perfectly, and I finally got my buoyancy down stat. But there was a bit of a damper on the dive which I have been trying to analyze and learn from for both the betterment of myself as a dive buddy, and also for the betterment of my dive buddy himself as a diver.

Its pretty basic. We were diving in a local lake, visibility was about 10ft and everything was going great until we reached about 35 feet. At this point, I was hovering and just enjoying the water while I took a look at my buddy (my father) who I found to be about 3 feet below me sitting on the bottom. This was something we had discussed that should not happen during our dives if at all possible as once the silt is stirred up, visibility goes to 0 very quickly, and stays that way. So I went down to be level with him, just a bit off my bottom, and I could see he was clearly trying to establish proper bouyancy. Partly, I was confused, because just a minute earlier he seemed to have it down pretty well (better than usual, still needs a tiny bit of work, but we're still both newbie divers), but I realized the compression might have effected something, so I sat and watched as he continued to get himself a few feet off the bottom. But my father seems to have one problem, and I suspect it to be linked to not weighting correctly, but he likes to use his BC/Inflator as a buoyancy crutch. So im watching, and I see him put one or two squirts of air into his BC, and I think to myself "Ok, thats fine, but thats got to be it Dad...", then he just keeps on putting more air in, and my mind goes to "Dad, were only at 35 ft, you go up a few feet, that air expands, and then your really going up". Then he goes to put MORE into his BC, still clearly trying to get neutral just with it (his breathing was not "rapid" but he was lacking breath control and the buoyancy aspects that come as a result of it). I reach over, get ahold of his inflator, and point to it shaking my head, trying to tell him not to put anymore in. So he takes a minute working on his buoyancy some more, and then goes and puts more into it, and he instantly starts quickly going up. I swim up and reach for it with one hand, and him with the other. I get him to look at me, see what I'm doing, and I dump enough air from his BC to stop the ascent and we slowly began to sink the 10 ft or so back to the bottom at this point. He returns to working on his buoyancy, and sure enough, goes right back to his inflator, which as I said I was considering ok in small amounts. But this time he just puts in way more than it turned out he intended to, and up he went rocketing up, unable to get ahold of the inflator to dump air, or maybe it was expanding more then it could dump, but he was moving up and fast, and I found myself without a buddy in sight within a few seconds. So I begin to swim up and I get sight of him on the surface, I make a safety stop for good practice for about a minute (I wanted to get up asap to see if anything was up). Eventually I got up to the surface, talked over what had happened, and called the remainder of the dive simply for the sake of nerves and obviously some work had to be done in terms of buoyancy.

So while it may have only been in 35 feet of water, this was my first experience involving A) a runaway ascent of a buddy, and B) Finding myself at depth without a buddy. Needless to say, there was a sinking feeling in my heart when I saw him shooting up, and I'm glad we were relatively shallow, but I am wanting to learn everything I can from this experience.

So on that note, I would like to ask if anyone has any suggestions or comments, for either myself, or my father. I know dumping air from his BC was probably a risky thing to do, but to me, I was treating the dive as if we were at 60 ft, and at the time a runaway ascent far outweighed a quick descent the 10 ft back to the bottom, so at least there is my reasoning at the moment it happened.

Beyond that, does anyone have any suggestions for my father as far as increasing his breath control, and as a result, his control over buoyancy? He generally tends to use about 140% more air than I do (for every inhale/exhale I take, he takes at least 2 full inhale/exhales), which I think is a result of some general discomfort in the water (he constantly does a kind of paddle with his hands and never really seems entirely comfortable, so I understand his heavy air use because he is clearly exerting himself with all the extra movement) and possibly some anxiety as he is a bit of a worry wart. He really does seem to enjoy the experience of diving based on post dive conversations, and I enjoy diving with him (albeit ending a dive with 2300 psi in the tank after 30 minutes can be a bit frustrating, but I dont mention that to him) all I can think of as far as solving some breath control/buoyancy problems would be more time in the water, so I figured I'd ask anyways. I'm just hoping when we land in Bonaire in 4 days the clearer water will help calm some nerves, and we'll be able to have some longer bottom times, either way I'll enjoy just being able to dive with my father.

Also, any suggestions on getting him off that "inflator crutch"? I suspect some better weighting might help with the problem.

Or maybe am I wrong to think of it as a crutch? It would make sense that people use their "buoyancy control device" to do just that, but maybe im the one doing something wrong by not using it in that way? I never have any air in my own BC except when im being lazy at the surface, but my buoyancy seems to be pretty good as far as being able to hover/stay a set distance from the bottom while moving around.

Looking forward to your thoughts...

Happy Diving!

 

[Erku]

Fellow noob here so believe anyone else over me!

That said. My mom had similar problems to your dad when she was learning, a tendency to either overinflate when she was trying to get neutral, forgetting the effect of a breath, or to fully deflate when she was trying to go down, resulting in the famous belly-flop-hops along the bottom of a new diver. In her case, and I think in your dad's, it's probably easiest to get back to the basics and practice fin pivoting to neutral buoyancy together until your buddy is comfortable with being conservative in his air addition.

I'm not sure what you mean by 'never' having air in your BC. Again, I may be totally wrong, but it sounds like you're just controlling your position in the water using your swimming? That's not really correct either. You should be able to just stop and float when necessary, and I think it does get necessary. Think helicopter, not jet.

 

[SeaHorse81]

I'm not sure what you mean by 'never' having air in your BC. Again, I may be totally wrong, but it sounds like you're just controlling your position in the water using your swimming? That's not really correct either. You should be able to just stop and float when necessary, and I think it does get necessary. Think helicopter, not jet.

Nicely done on the helicopter analogy.

To OP, you will find as you go to greater depths that you have to use the BC, and will appeciate it greatly.

A suggestion for your dad would be to spend some more time on basic buoyancy control in general (time for another pool session before Bonaire?), to make small adjustments at a time in the BC (as you said), but also to allow more time for those adjustments (in both lungs and BC) to take effect. If he's tending to rush, perhaps he's expecting an instant reaction to his BC adjustments and assuming that lack thereof means he hasn't done enough. Just a little puff, then hang out for some seconds to see what happens. If nothing, then another little puff and wait, etc.

Best to go slow and avoid the need for big over-corrections (which, in a way, is what an uncontrolled ascent is). Neutral is a beautiful thing, and you don't get it by rushing.

 

[TSandM]

Has your father done a good weight check? Having to put that much gas in a BC at 35 feet kind of suggests he's overweighted, and being overweighted makes neutral buoyancy a very tenuous thing.

It also sounds as though your father may not be patient enough to wait after each addition of air to the BC, to see what the results will be. This happens a lot -- students just don't realize that you need to wait at least the length of a breath or two to be able to fully evaluate what your last addition (or vent) has done.

Something I tell students and new divers is that, when you are diving with a defined floor beneath you, it is ALWAYS better to make a buoyancy error in the direction of the floor than to do an unintended ascent. This is true even with our silty sea floor here in the Sound. You're better off sitting on the bottom and waiting for the water to clear a bit, than you are rocketing to the surface.

One of the things I have done with students in the pool is to have them follow me as I swim from the shallow end to the deep end and back. At the end, I ask them, "How many times did I use my inflator to do that?" They are usually quite surprised to have seen that I didn't touch it at all. This seems to motivate them to figure out how to do the same thing.

Your dad sounds as though he could definitely benefit from some more pool time, if that's something you guys can manage.

 

[Selchie in LB]

Togalive Thanks for the post. I too have been struggling with buoyancy. In fact I did the same thing as your father only I ending up at the surface from about 45ft. Yikes! This on literately on my first dive after being certified. I add that note because I believe I experienced what I will call "sink the student"! Instructors over-weighting beginners to get them on the bottom to practice drills.

After many talks with people and reading posts here, I have cut my weight and learned to anticipate. Initially, just like your father I didn't take time to wait for the input of air to take effect, thus over inflation. I have also learned that breath control is very difficult when I was over weighted. The anticipation part comes when you are ascending. I am much better at "sensing" my buoyancy and can feel depth changes. I don't really know how else to explain what I mean, except that I am sure other divers while get it. The anticipation really comes into play when ascending (not surfacing) just moving up as I said earlier. It really is in the first 20 feet or so that air expands rapidly. That helped me understand what was happening.

As for sucking air, yes I too was going through tanks in 20 minutes on 30-40 foot dives because I was struggling to stay off the bottom and push that much extra weight though the water. You have a real advantage in that you and your father can practice skills. I do not have a one buddy that I constantly dive with and while people have been great with diving with a noobie, they haven't wanted to curtail the dive to just skills. Refer back to the buoyancy skills in the manual. The weight check, at eye level etc. AND, when descending EXHALE, EXHALE EXHALE.

Good luck and keep diving! He will get it.

 

[Erku]

Another trick that might help is to practice, on land or in shallows, having him feel where the location of his bcd emergency dump cord is. On the BCDs we used in my training, the controlled air release was too slow to stop a buoyant ascent, and even the emergency release from yanking the bcd inflator tube wasn't as fast as pulling the dump cord. My wife has a lot of troubles finding hers and we've determined that would probably be the easiest way for her to abort buoyancy accidents. She has managed to stop herself once that way but the other two times, just fumbled for it and then found herself on the surface with sore ears. On the flipside I kept having issues with my normal air release in early training (just kept forgetting to hold it up) and used the dump cord a lot for the first couple pool dives; since I know where it is, I've stopped myself from buoyancy accidents several times. now I just have to practice not having the accidents in the first place ...

 

[gcbryan]

As mentioned, it sounds like he is overweighted and too quick with the addition of air. Another factor that may apply is that if this is happening on initial descent he probably isn't taking the temporary downward force of the descent into account.

Sometimes it's good to add a bit of air and then kick forward for just one stroke just to stop the downward force from the descent. After that, as was mentioned, it's just a matter of adding air and waiting for it to take effect before adding more air.

 

[Bubbletrubble]

I have to agree with much of what has already been said.

With regard to what your dad can work on:

• He should do a proper weight check. The specifics of doing this should have been covered in class by the OW instructor. His OW class materials will have a detailed description of how to do this, too. The method I learned for determining the right amount of weight is as follows: at the surface with reg in mouth while wearing all of his gear, a diver should add enough lead so that the water is at eye level while he holds a normal breath -- with no air in the BCD and on a near empty tank. Make sure that all of the bubbles are worked out of the wetsuit before doing the weight check. FYI, the same technique can be performed with a full tank but the amount of weight needs to compensate for the remaining gas in the tank. Recall that as gas is used up from the tank, it becomes more positively buoyant. For the typical AL80, that's about 5-6 lbs; therefore, if the diver did the weight check with a full AL80, he would add 5-6 lbs. to whatever amount of weight that was used during the weight check. Anytime gear is changed (particularly when using a different BCD/tank/wetsuit), it's best to do another weight check. I cannot emphasize that enough.
• Your dad needs to be patient and wait for buoyancy effects to take hold. As has been mentioned, there is a lag time involved between when the diver hits the power inflater button and when the effects of positive buoyancy are felt. When attempting to establish neutral buoyancy, it's best to add air to the BCD in small bursts. In fact, I'd argue that the diver should be adding frequent, small bursts of air to the BCD throughout the initial descent. I've seen beginners who empty their BCD completely at the surface, become a dirt dart, create a silt cloud, and then start adding air to the BCD while kneeling on the bottom. Similar mistakes are made during the ascent. When the novice wants to ascend, he'll inexplicably dump all of the air in his BCD (presumably to guard against a runaway ascent), become severely negatively buoyant and then kick for the surface. That's simply not how to do it. Descending/ascending under control means being able to stop at whatever depth you want to...without kicking. For the most part, I only kick during my descent if I'm diving in a current or I need to re-position myself with respect to my buddies. On your next dive with your dad, during the initial descent, both of you should try to stop at depths of 5, 10, 15, 20 ffw and hover for a minute at each depth. During ascent, try to make the same stops. This is a wonderful exercise because it will get both of you in the habit of adding/dumping air to the BCD in short bursts to establish neutral buoyancy. It should also keep you guys from crashing into the coral at Bonaire.
• More pool time would be a good thing. Both of you guys should practice hovering. Learning to hover effortlessly, without waving your arms about and kicking, will make diving easier and will help immensely with air consumption. More practice = better buoyancy control = better air consumption = more fun.
• Personally, I don't like to think of manipulating the power inflater as a "crutch." It's there to help adjust for the two main changes in buoyancy throughout the dive: (1) compression/expansion of neoprene dependent upon ambient pressure changes and (2) the loss of gas in your tank. As you pointed out, how a diver breathes helps with fine-tuning buoyancy control (remember the fin pivot drill in OW class?). With practice, a diver figures out how to make economical use of the power inflater.
• For the most part, your dad should focus on breathing "normally." This means breathing with a regular rate/rhythm and taking normal-sized breaths. He should be doing this during descent, while maintaining depth, and during ascent...and making other buoyancy adjustments with the BCD. Understandably, this is difficult for a beginner since breathing underwater is a pretty novel experience.

With respect to your diving and your role during the uncontrolled ascent and buddy separation:

1. If you are properly weighted, using a full tank, and wearing a thick wetsuit, you will almost certainly have some air in your BCD at depth at the beginning of the dive.
2. In the scenario you described, I would have performed a controlled ascent (no faster than 33 ft/min) and skipped the safety stop completely. Based on your dive profile, there's no way that you were nitrogen-loaded enough for it to be a concern. The nice thing about what you did (stopping for 1 minute at safety stop depth) is that it forced you to slow your overall ascent rate. Your instincts were correct, though. You recognized the fact that your buddy, following an uncontrolled ascent, may have been in dire need of assistance at the surface. Getting there as quickly as you could in a safe manner was the right thing to do. Something to consider is how you would manage your ascent profile if you lost your buddy and failed to locate him after looking for him for one minute. Under what circumstances would it make sense to do a safety stop? Under what circumstances might it make sense to skip the safety stop?
3. It's difficult for novice divers to help each other out with buoyancy control issues. I think you did great when you helped your dad dump air the first time he floated up 10 ft. That's what a good buddy does. I also think you showed great maturity in discussing what happened afterward. Continue to do this. Having such discussions can be a delicate matter, particularly when your dive buddy is a family member. Try your best to be diplomatic.
4. Adjust your expectations for your upcoming dive vacation. Expect 30 minute dives for now. Look forward to the fact that you two will be having a great time, diving in a warm place -- all while doing some quality father-son bonding. I think you'll be surprised by how much fun you'll have regardless of how long each dive is. By the end of the week, your dive time will increase. You'll see.

Not too long ago I did a dive with a novice who held onto her power inflater cocked over her head for the entire dive. She was doing things that most beginners do -- trimming out more vertical than horizontal, kicking constantly, swimming with hands, adding/dumping air to the BCD while maintaining the same depth, running through her air very quickly. You know what, though? She still got to see the 5 ft. long giant sea bass that swam by us. She still had a great time, was eager to learn how she could improve, and couldn't wait to get back in the water. That's a successful dive in my book.

I hope you find some of this helpful. Thank you for sharing your experience. Have fun out there...

 

[Erku]

Great read bubbletrubble!! Thanks!

 

[Dhboner]

The only thing I could add is that I would have skipped the safety stop entirely. Your dad's out of control ascent could have caused medical issues that required immediate attention. Had he been holding a breath from even 30 feet he could have been in trouble (thank God he wasn't).

You can practice a safety stop anytime...your buddy's well-being is your first concern. I'm definitely not ragging on you since you handled everything really well...it's just a thought for the future.

Bob