ascending with unconscious victim
- Thread starter lanun
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There are too many unknown variables to answer this question; for example, how much air is in the BC, what kind of exposure protection, the depth, the profile resisting ascend, etc.
The key is that if properly weighted, without an outside influence, dropping weights invariable results in an uncontrollable runaway ascent.
My comment was not meant to be personal, it was simply an observation. If you choose to take it personal and call me a poopy head, so be it; trust that I wont loose any sleep over it.
You have submitted that you are an instructor and are proposing what I and others feel is a very unsafe practice. Several times you have been asked why you would drop the weights rather than adding air to control buoyancy and I had not seen a coherent response but instead, cute slogans like The BEST rescue is one that never has to happen, which in the context of a discussion of an unconscious diver, seems out of place. To me that looks like obfuscation.
Mike
The Chairman
Chairman of the Board
than the occurance of a runaway would be minimal. Not all of your weight should be ditchable.
Again... we do this in the pool and from depth enough to see that there is no runaway if the weights are 20# or less. But adding 20# of buoyancy at 66 ft becomes 60# of buoyancy by the time you hit the surface... unless you hopefully let it out. Under the stress of the rescue, I would gladly deal with the former and not the latter.
BTW, glad you think the slogans are cute... they are meant to get your attention and possibly make you think.
Again... we do this in the pool and from depth enough to see that there is no runaway if the weights are 20# or less. But adding 20# of buoyancy at 66 ft becomes 60# of buoyancy by the time you hit the surface... unless you hopefully let it out. Under the stress of the rescue, I would gladly deal with the former and not the latter.
BTW, glad you think the slogans are cute... they are meant to get your attention and possibly make you think.
Waterlover
Contributor
How many of you have actually had to do a rescue in this situation?
I've never ascended an unconscious diver.
I did bring a diver who had an equipment failure and who was panicked to the surface. I used her BC.
I dumped gas from her BC and from my wing as we ascended.
There were no issues.
I can't think of a good reason to drop weight when you can ascend them using the victim's BC. If you can't control them due to your own panic, then you should practice the skill until you can.
That said, most of my diving is in the Northeast in a drysuit with heavy steel tanks. Ditchable weight is only used by those divers in singles. If I were to drop the belt, they could race my liftbag to the surface.
I did bring a diver who had an equipment failure and who was panicked to the surface. I used her BC.
I dumped gas from her BC and from my wing as we ascended.
There were no issues.
I can't think of a good reason to drop weight when you can ascend them using the victim's BC. If you can't control them due to your own panic, then you should practice the skill until you can.
That said, most of my diving is in the Northeast in a drysuit with heavy steel tanks. Ditchable weight is only used by those divers in singles. If I were to drop the belt, they could race my liftbag to the surface.
otter-cat
Guest
The more posts I read in this thread, the more I think that the issue of WHERE you are diving (in terms of the amount of weight and exposure protection) should be taken into account by the powers that be who develop the training manuals and such.
As a diver in the PNW who wears a 7mm neoprene DRYsuit, and has several extra pounds of body fat, I wear quite a bit of weight. Most people around here are either wearing drysuits or 2-piece 7mm wetsuits, and almost NO one around here wears LESS than 20 lbs of weight (except for a few fairly lean males who have steel bps and steel tanks.) Most people wear about 25-35 lbs in this area. I wear a little more.
In Florida and other warm water areas, I can see where ditching some of a victim's weight might be relatively fast & easy, and might not create that much of a skyrocket effect, particularly if you are holding on to them, and couteracting the victim's buoyancy by making yourself more negative. Then all you have to do is control your own bc dump valve instead of 2 of them, and hang on to the victim. If you accidentally let go, they go to the surface & may or may not suffer injury as a result, but at least you don't become a 2nd victim. Hopefully you won't let go and can control the ascent the entire way up.
HOWEVER, though much ignored in most of the instructional diving literature I've seen (which is admittedly primarily from PADI) those of us who dive in cold water are in MUCH greater danger if our weightbelts are lost. PADI (and other agencies and instructors) should REALLY take this into account when advising divers on rescue techniques. Even if certifying divers in warm water, those divers are then certified to dive in cold water too, and should have some knowledge that cold water conditions require some different techniques in a rescue.
That said, because we cold salt-water divers wear so much weight, there are many cases where divers are wearing weight integrated BC's AND a weight belt, so ditching just one of the two might not be as catastrophic, although my personal experiences make me skeptical of losing even half the weight. On the other hand, there are also lots of divers around here that just use belts (or just use bc weight-pockets.) So, as usual, the answer would be to LOOK and THINK about what you need to do based on the situation.
I would in general be VERY hesitant to remove any diver's weight belt at depth around here (cold water). And now that I think about it, if the weight belt doesn't weigh that much (i.e. warm water), then you probably shouldn't need to remove their weightbelt to be able to easily maneuver them to the surface. While I can accept that in warm water, the potential damage from doing so is less than in cold water, I do find it somewhat alarming that certain courses seem to recommend immediately ditching a victim's weight at depth as an "automatic" part of the procedure. I would much prefer to see "EVALUATE the buoyancy potential of the diver, and act accordingly to get them to the surface as safely as possible."
I shudder to think what would happen to me if, as a victim, and assuming I'm still alive, my would-be rescuer dumps my weightbelt at depth as a matter of course.
Incidentally, although I hate to admit it, I did once accidentally lose my weightbelt at about 50 fsw, in my usual cold water equipment. I retained about half of the weight I was wearing at the time, in my bcd. Even with losing only half, I did an uncontrolled skyrocket to the surface, at a rate which I doubt could have been controlled, even by a diver holding me tight. I consider myself very lucky not to have gotten bent, probably because I had not been at depth for very long when it happened. If I'd been in warm water at the time, I'm sure the ascent wouldn't have been as scary in terms of speed, but out here, I jumped more than halfway out of the water when I reached the surface. I REALLY hate to think how fast the ascent would have been if I'd lost ALL my weight in this water (or had it removed.)
Sorry for the long post, but I thought these things merited being mentioned.
Dive Safe,
otter-cat
As a diver in the PNW who wears a 7mm neoprene DRYsuit, and has several extra pounds of body fat, I wear quite a bit of weight. Most people around here are either wearing drysuits or 2-piece 7mm wetsuits, and almost NO one around here wears LESS than 20 lbs of weight (except for a few fairly lean males who have steel bps and steel tanks.) Most people wear about 25-35 lbs in this area. I wear a little more.
In Florida and other warm water areas, I can see where ditching some of a victim's weight might be relatively fast & easy, and might not create that much of a skyrocket effect, particularly if you are holding on to them, and couteracting the victim's buoyancy by making yourself more negative. Then all you have to do is control your own bc dump valve instead of 2 of them, and hang on to the victim. If you accidentally let go, they go to the surface & may or may not suffer injury as a result, but at least you don't become a 2nd victim. Hopefully you won't let go and can control the ascent the entire way up.
HOWEVER, though much ignored in most of the instructional diving literature I've seen (which is admittedly primarily from PADI) those of us who dive in cold water are in MUCH greater danger if our weightbelts are lost. PADI (and other agencies and instructors) should REALLY take this into account when advising divers on rescue techniques. Even if certifying divers in warm water, those divers are then certified to dive in cold water too, and should have some knowledge that cold water conditions require some different techniques in a rescue.
That said, because we cold salt-water divers wear so much weight, there are many cases where divers are wearing weight integrated BC's AND a weight belt, so ditching just one of the two might not be as catastrophic, although my personal experiences make me skeptical of losing even half the weight. On the other hand, there are also lots of divers around here that just use belts (or just use bc weight-pockets.) So, as usual, the answer would be to LOOK and THINK about what you need to do based on the situation.
I would in general be VERY hesitant to remove any diver's weight belt at depth around here (cold water). And now that I think about it, if the weight belt doesn't weigh that much (i.e. warm water), then you probably shouldn't need to remove their weightbelt to be able to easily maneuver them to the surface. While I can accept that in warm water, the potential damage from doing so is less than in cold water, I do find it somewhat alarming that certain courses seem to recommend immediately ditching a victim's weight at depth as an "automatic" part of the procedure. I would much prefer to see "EVALUATE the buoyancy potential of the diver, and act accordingly to get them to the surface as safely as possible."
I shudder to think what would happen to me if, as a victim, and assuming I'm still alive, my would-be rescuer dumps my weightbelt at depth as a matter of course.
Incidentally, although I hate to admit it, I did once accidentally lose my weightbelt at about 50 fsw, in my usual cold water equipment. I retained about half of the weight I was wearing at the time, in my bcd. Even with losing only half, I did an uncontrolled skyrocket to the surface, at a rate which I doubt could have been controlled, even by a diver holding me tight. I consider myself very lucky not to have gotten bent, probably because I had not been at depth for very long when it happened. If I'd been in warm water at the time, I'm sure the ascent wouldn't have been as scary in terms of speed, but out here, I jumped more than halfway out of the water when I reached the surface. I REALLY hate to think how fast the ascent would have been if I'd lost ALL my weight in this water (or had it removed.)
Sorry for the long post, but I thought these things merited being mentioned.
Dive Safe,
otter-cat
Now I get it. We're talking apples and oranges. In a 3mil suit I only need a couple of kg of weight in salt water and nothing in fresh. Your technique would probably work in those conditions.
Question: do you make your students aware of the fact this only works in local conditions? Around here we dive in drysuits most of the year. If you dropped the weights from a victim in a drysuit you'd be dumping probably 10 kg or more. That's a big difference. The nice thing about using the BCD is it's a one-size-fits-all solution.
Here's something to think about: If your students move, or go on vacation somewhere else, then their training won't apply any more. You're producing students who think that dropping weights will lead to a controlled buoyant ascent but in most of the world it will give you an uncontrolled buoyant ascent because of the thicker suits. You have the option to teach them a one-size-fits all solution. I don't understand why you wouldn't do that.
R..
The Iceni
Medical Moderator
Hi Lanun,
Sorry it has taken me a while to get to this thread but it is an important one as many of the replies confirm that few divers really understand the principles of diver rescue and what can actually be done in practice. I would not want what happened to me to to happen to someone else. I would like to provoke some discussion as I am sure what follows is not what is taught.
In a nutshell I suffered shallow water blackout and there was a delay before I was rescued and then I was shot to the surface like a rocket as you can see from the attached profile.
From my rather jaundice perspective I would suggest the following points are the important ones.
(1) Do not become a casualty yourself
(2) The casualty will die if he is not brought to the surface.
(3) Do not do anything that might cause further harm.
(4) Remain in control
I feel it is difficult enough for a diver to control his own buoyancy so I would suggest it is extremely difficult to perform a really controlled buoyant lift (your example 1) let alone try to handle four air cells if both you and your buddy are diving dry. Thus your examples 3 and 4 simply add to task loading (1). If you lose your grip on your buddy during the ascent and you use your version 2, he will sink while you rocket to the surface. (1,2,3 and 4 all then apply)
Aspiration of water will cause acute lung injury and salt water causes laryngospasm and risks subsequent pulmonary barotrauma. It also causes a caustic injury to lung tissue prejudicing future resuscitation so any attempt at ventilating an unconscious casualty underwater risks further injury by the aspiration of water! (3)
Much of the air forced into the oropharynx (by mouth to mouth/nose or from an actively purged regulator) will find its way into the stomach, this will expand on the ascent provoking vomiting and risking gastric barotrauma (3). All of these detract from the important task (2) and add to task loading (1).
Although the casualty must be brought to the surface as soon as possible you have several minutes before the lack of oxygen causes major problems, as my case appears to prove, so I am yet to be convinced that a rescuer need ever attempt ventilation.
Missed deco stops may lead to DCI but that is usually easy to treat, near drowning not so (2).
If a diver is fitting from Oxtox it would be foolish to approach him (1) and if you brought him to the surface when in the tonic/clonic state you risk causing barotrauma (3) but this soon passes to the flaccid phase when rescue will be safer. Such a deeply unconscious casualty may appear to be dead, as I did, but all muscles are relaxed including those controlling the glottis so I consider the risks of pulmonary baraotrauma in an unconscious casualty are widely exaggerated. (Look at my profile once more.)
As I discussed in the referenced thread, when I lost consciousness I needed to be on the surface and the CBL (your No. 1) approach seems to me to be by far the best option. If the ascent gets out of control, as it obviously did during my rescue by very experienced divers, you must let the casualty go (1 & 4) but at least he will get to the surface where you can follow or others attend to him (2).
Any comments? :doctor:
P.S. Do not give up on basic life support even if you think there is no hope!
when i first asked the question, it appeared relatively finite in scope - since the source of education is books and instructor. but as the past posts (form a variety of perspectives, yours included) suggests, there's a heck of a lot to consider. one being don't be a victim yourself, the other - DCS is treatable, being dead isn't.
on the other hand, if i made the decision to help, i will probably go to the limit of my skill and i think that limit (up to this point in my limited experience) is possibly where i think is my personal ability to remain in control during ascend.
even if this post garners another hundred responses, i wouldn't be able to come-up with that perfect response flow checklist.
i think the series of posts will help me at least shortlist the options to consider when confronting with an unconscious diver underwater.
in a way, i am kinda happy i have not completed the OW portion of my RD cert. because even with plastic in my wallet, i know i still have a lot more to learn.
on the other hand, if i made the decision to help, i will probably go to the limit of my skill and i think that limit (up to this point in my limited experience) is possibly where i think is my personal ability to remain in control during ascend.
even if this post garners another hundred responses, i wouldn't be able to come-up with that perfect response flow checklist.
i think the series of posts will help me at least shortlist the options to consider when confronting with an unconscious diver underwater.
in a way, i am kinda happy i have not completed the OW portion of my RD cert. because even with plastic in my wallet, i know i still have a lot more to learn.
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