Woman critical after West Van scuba diving accident - Canada

[Crush]

Hopefully with a bit of time, more information will come out. Analyzing bunk and hypothesis really amounts to nothing more than an academic discussion which IMHO is best done anonymously without reference to specific people's situations. IF we don't KNOW, we DON'T know. I personally feel its best to look at and seek fact rather than rely on conjecture to discus causalities.

Re-posted from http://www.scubaboard.com/forums/566581-post1.html - special rules on the Accidents and Incidents forum.

Special rules - Please Read

Originally Posted by Rick Murchison:

The purpose of this forum is the promotion of safe diving through the examination and discussion of accidents and incidents; to find lessons we can apply to our own diving.

Accidents, and incidents that could easily have become accidents, can often be used to illustrate actions that lead to injury or death, and their discussion is essential to building lessons learned from which improved safety can flow. To foster the free exchange of information valuable to this process, the "manners" in this forum are much more tightly controlled than elsewhere on the board. In addition to the TOS:

(1) You may not release any names here, until after the names have appeared in the public domain (articles, news reports, sheriff's report etc.) The releasing report must be cited. Until such public release, the only name you may use in this forum is your own.
(2) Off topic posts will be removed and off topic comments will be edited.
(3) No flaming, name calling or otherwise attacking other posters. You may attack ideas; you may not attack people.
(4) No trolling; no blamestorming. Mishap analysis does not lay blame, it finds causes.
(5) No "condolences to the family" here. Please use our Passings Forum for these kinds of messages.
(6) If you are presenting information from a source other than your own eyes and ears, cite the source.
(7) If your post is your hypothesis, theory, or a "possible scenario," identify it as such.

Thanks in advance,
Rick​

It is important for us as a community to assess and discuss diving accidents and incidents as a means of preventing them. However, once emotions are involved, intelligent discussion becomes next to impossible. If the moderators feel that the discussion is getting out of hand in any thread they may close or remove the thread, with or without notice.

Uncle Pug

​

This forum is about many things, including respectful speculation.

 

[MauiScubaSteve]

....If they were still on ascent when she gave up the reg and sank, then no one would have attempted to remove weights yet.

Although it's certainly an attractive hypothesis that she was overweighted, I can also imagine a scenario where they establish the air-share and begin ascending in the vertical position, slightly negative and swimming as OW students are so often taught to do. If she then embolized and dropped the reg, she would stop swimming and therefore sink.

I don't like vertical, negative swimming ascents, personally.

I for one will continue to advise negative swimming ascents to my OW students that are healthy enough to dive (the ones that did not lie on the medical release).

If the diver is properly weighted for neutral at the surface with an empty tank, then they would only be slightly negative at less than 2 ATM (bottom 45' - divers on ascent). Following the "book" on weighting would mean the diver is even less negative at less than 2 ATM with an empty tank. Hypothesizing embolizing during alternate ascent seems to be stretching for a reason to post your dislike of negative ascents.

For a negative vertical ascent to have had any part in this tragedy I think there were at least 2 failures/faults (probably more than 3) prior to any problem due to negative ascent.

 

[DandyDon]

I am not clear on the differences in opinions here on negative ascents? I like using one so I can duck back down vertically & quickly if I see a craft approaching.

It turns out that I unknowingly met the man who was involved in this accident. He came into the shop on Friday to replace his mask that was lost during the ordeal. I had posted for that mask last week: mentioned here At the time of posting that thread I had no clue who/what... nada

I want to put that in as a plug to try and generate a bit of local awareness to get back the first mask that hasn't leaked for him in a while... if anyone sees it... He seemed to be quite fond of it. He seemed still quite shaken, rightly so, but came in to speak with two of his friends who work there... mostly for social, but the mask did come up.

You might also post that in our new L&F forum: Lost, Found and Stolen - ScubaBoard

As for the accident victim, as of this past Friday, apparently, she was still not conscious. From my understanding it seems to still be induced coma. He did not mention or release any details around the shop and NO-ONE is going to discuss it until he initiates.

Glad to hear that she is still with the living and hope the best for her. We have actually had divers survive accidents and induced comas then come read the discussions about their accidents here mostly because they had no memory of the accident. I awoke from a car accident with no memory of it once; odd feeling, especially when taken back to the scene.

Too bad y'all are not discussing this with him as post incident stress can be very heavy on a rescuer, successful or not, and talking about the accident can be the best therapy. The Padi Rescue course has a chapter on it, but there is really little available on the web - an under discussed risk in itself. I'd like to give the guy a medal myself, and encourage him to accept that he was the lady's only hope and did the best he could. I don't know what courses you have taken as you seem defensive about that subject on your profile, but if you've had any agency's Rescue course perhaps you have heard of this?

Hopefully with a bit of time, more information will come out. Analyzing bunk and hypothesis really amounts to nothing more than an academic discussion which IMHO is best done anonymously without reference to specific people's situations. IF we don't KNOW, we DON'T know. I personally feel its best to look at and seek fact rather than rely on conjecture to discus causalities.

As has been mentioned a few times here, our goal in discussing accidents is only to prevent similar ones in others, even tho we seldom have many facts and can only speculate on possible causes and preventions. Whether or not this lady did make it to the surface, it is good to remind ourselves of the need to be able to establish buoyancy in an surface emergency should that happen to any of us, by orally inflating BCs or whatever flotation device one uses, dumping weights or however one manages without dumpable weights, etc. Drownings after surfacing without establishing buoyancy have been all too common on this forum; my bud & I drill on oral inflating and dumping every trip just in case panic tries to take over one of us in such a case.

 

[tregrrr]

Re-posted from http://www.scubaboard.com/forums/566581-post1.html - special rules on the Accidents and Incidents forum.

Special rules - Please Read


​

This forum is about many things, including respectful speculation.

yep.

As long as we remember to keep straight in our minds and discussions which is what: speculation versus fact.

I get a foul taste when speculation becomes "fact" as when people rely on the(ir) conjecture in place of facts and often confuse the two. I appreciate a good mental exercise as much as the next person, and do recognize the benefits, but in these cases I feel it beneficial to keep our perspectives clear.


@Don
I did not feel it my place to initiate any further conversation with the gentleman as he was in to speak with a couple long time friends, and I had merely met him a couple time prior in passing. I am well aware of the benefits of post incident discussion, but again he came in to speak with his friends, I am just a casual acquaintance. Plus it wasn't until after he left that I put two and two together. My mind works slower out of water.
T

 

[Crush]

...If the diver is properly weighted for neutral at the surface with an empty tank, then they would only be slightly negative at less than 2 ATM (bottom 45' - divers on ascent).

halemanō, I haven't done the math for cold water, but the diver was in the Pacific Northwest. Since she was new to diving, she was likely in a 7mm wetsuit (possibly two-piece) rather than in a drysuit. Your numbers might be correct - perhaps at 33 ft she should be "slightly negative" in a 7mm wetsuit. However you live in Hawaii (I am envious, by the way...). Have you accounted for the difference between a 3mm suit and a 7mm suit? I have got to tell you that I LOVE Florida diving since I feel light as a feather on the boat and my buoyancy rocks when I don't have to contend with 7mm x 2 or a drysuit...

 

[kazinvan]

I know staff at VGH familiar with the case though I'm not sure how much should be posted on this board... Any input appreciated.

 

[John C. Ratliff]

halemanō, I haven't done the math for cold water, but the diver was in the Pacific Northwest. Since she was new to diving, she was likely in a 7mm wetsuit (possibly two-piece) rather than in a drysuit. Your numbers might be correct - perhaps at 33 ft she should be "slightly negative" in a 7mm wetsuit. However you live in Hawaii (I am envious, by the way...). Have you accounted for the difference between a 3mm suit and a 7mm suit? I have got to tell you that I LOVE Florida diving since I feel light as a feather on the boat and my buoyancy rocks when I don't have to contend with 7mm x 2 or a drysuit...

This is a very good point; diving in the Pacific Northwest is much different, and one of the reasons BCs became available. We were trying over the years to find something that allowed us to be neutral at the bottom (say 45 feet) and also neutral at the surface. I did a number of experiments on this in the 1970s, and wrote about them in NAUI News. I also published them in IQ6 or IQ7 (the Sixth and Seventh International Conferences on Underwater Education). One of those experiments was to dive in a fresh water lake (Clear Lake, east of Eugene, Oregon) and take off my 16 pound weight belt at 33 feet depth. I tied it onto the anchor line, and was completely neutral for buoyancy at that depth in my full wet suit (water temperature was 39 degrees F, about 4 degrees C). I was also neutral with the weight belt on the surface. We were at an altitude of about 3000 feet too (900 or so meters). But that's a 16 pound difference in buoyancy! It is similar in salt water at sea level, although due to the difference in SG of salt water, the wet suit may retain some buoyancy at 33 feet. That would be compensated for by the different amount of weight that the diver needed to wear (for me in the 1970s, it was 22 pound in salt water verses the 16 pounds in fresh water; today it is greater on both environments as I am a bit fatter ).

The reason BCs exist is because we cannot by breath alone compensate for the loss of buoyancy of a wet suit. Dry suits have their own buoyancy compensation systems, and in the 1970s were used without BCs (mostly Unisuits). But I don't think that a fully negative swimming ascent is wise in cold waters with a wet suit. Dacor came out with an interesting system which only had to be compensated once, the Nautilus BC, and thereafter it either bled off air as the diver rose without increasing buoyancy (it was a hard-shell system, and operated much like a submarine), or added air to compensate for pressure changes as the diver descended. We don't have that anymore, so swimming to the surface with a compensated BC will allow air to expand, and it must be bled off. But to try a swimming ascent when fully negative at depth will put quite a physiological work load on the diver.

One other thought, which does not apply to this particular situation but I don't think is being taught anymore, is that free divers (usually spearfishers) in the Pacific Northwest would remove their weight belt and carry it in their hand if they had overstayed their breath on breath hold dives. Then, if shallow water blackout occurs, the weight belt is automatically dropped as the diver can no longer hold it while unconscious. I actually used this technique a few times in my early days of diving, but made the surface okay and didn't drop the weights.

SeaRat

 

[DCBC]

One other thought, which does not apply to this particular situation but I don't think is being taught anymore, is that free divers (usually spearfishers) in the Pacific Northwest would remove their weight belt and carry it in their hand if they had overstayed their breath on breath hold dives. Then, if shallow water blackout occurs, the weight belt is automatically dropped as the diver can no longer hold it while unconscious.

Your post brought back many memories John. I remember on a deep dive (100 feet or so) using a "Mae West" with a 1/4 inch wet suit. You would try to be slightly underweighted at the surface (neutral at 10; for decompression purposes), had to kick to get down and kick like hell to get back-up. LOL

The ability to release the weight belt was important in an emergency and was often a diver's (or buddy's) only salvation. Today, there is a tendency to not think this as important as it use to be. Technology has all the answers, or at least that's a prevalent course of thought that I don't fully agree with.

Even a Wet Bell used in saturation diving has an emergency release weight system and every operator knows when it should be used. Sometimes the surface is everything; without it there's only death.

 

[TSandM]

I don't like negative, swimming ascents because they are inherently unstable. The diver is required to match swimming effort to the precise ascent rate they want to achieve, and if they try to stop, they have to be very precise in that matching, or inflate the BC very precisely.

A floating ascent, where one is never very far off neutral and is not finning, is much easier to arrest for stops, and if the diver is distracted or task loaded in some way, they will not begin to sink. It's more difficult to learn, though.

 

[MauiScubaSteve]

I don't like negative, swimming ascents because they are inherently unstable. The diver is required to match swimming effort to the precise ascent rate they want to achieve, and if they try to stop, they have to be very precise in that matching, or inflate the BC very precisely.

A floating ascent, where one is never very far off neutral and is not finning, is much easier to arrest for stops, and if the diver is distracted or task loaded in some way, they will not begin to sink. It's more difficult to learn, though.

You seem to be saying that learning to negative ascend precisely enough to match swimming effort to planned ascent rate and precisely inflate vest at stops is easier than learning precise floating ascents. I'm not seeing much down side here.

One of my favorite quotes from an ex-boss is "I'll drop like a rock to save you and even your expensive camera, but if you pop to the surface like a cork I'll be with you shortly." As a buddy, guide or instructor I will have less problem dragging you up than I will flaring with an ankle.

In this situation, a negative ascent from 45 fsw is not in the top 3 reasons the person needed reviving.