TSandM: Missing Diver in Clallam County, WA

[JackConnick]

[QUOTE I can’t imagine that it is consistent enough for anyone to answer that question.

Thanks, have dived in 9 to 10 or so knot--was wondering what this maxes out @.......

Michael Phelps swam the 200 at 4.34 MPH. That's 3.77 knots.

In real world we tried swimming at a fair rate alongside our boat (no dive gear). We could do about 1 knot or so for any distance.

 

[PeterNBiddle]

I don't think I could hold station in anything much over 2kt. At 9-10kt only the fastest of fish could hold station. A diver in this kind of current wouldn't be so much "diving" as being thrown around at the whim of the ocean. For comparison, the Rhine river, which flows fairly quickly for a large river, has currents at about 4-5kt.

R..

Having dived a 4, I know that I personally would thumb anything over that.


Sent from my iPad using Tapatalk

 

[Ayisha]

... Also if she embolized or had a medical event then "blown away" likely means "rendered unconscious and taken away by the current".

I also wonder if she could have possibly embolized. She apparently went from about 125 or 130 feet to about 70 or 75 feet in a short time, and was actively trying to deal with the ascent when last seen...

 

[gcbryan]

This page suggests a current offset which would put them at slack for Duncan Rock:

Duncan Rock



---------- Post added August 29th, 2015 at 02:45 PM ----------



Peter posted that the current on the surface was not bad, which is probably why the dive was not called on the surface. Surface conditions don't necessarily translate to conditions at depth. It can be nasty on the top and calm on the bottom or vice versa. In an area with lots of bottom contouring and canyons currents can be unpredictable (even along pretty smooth shorelines I've seen weird currents that haven't behaved like I expected).

Also if she embolized or had a medical event then "blown away" likely means "rendered unconscious and taken away by the current".

Yes, of course to all of the things that you've mentioned. My experience is the same. I'm just curious as to what the current was like for the other divers. If Lynne had a blood clot that was affected with rapid changes in pressure that could explain this situation.

I'm just curious as to the actual current at depth. I think it's quite likely that her body is somewhere in the vicinity however even if neutrally weighted she isn't going to stay at midwater forever for many reasons.

If we are lucky she could end up at Tatoosh or Cape Flattery (as well as just on the bottom anywhere offshore of course.

As for as what we can learn from this dive I think it's just to live life to the fullest as Lynne did. I don't think anyone here that knew her has posted anything to suggest that she didn't know what she was doing or that she did anything wrong.

There is the "Passings" forum for condolences and this one is to discuss what happened.

 

[lamont]

Yes, of course to all of the things that you've mentioned. My experience is the same. I'm just curious as to what the current was like for the other divers. If Lynne had a blood clot that was affected with rapid changes in pressure that could explain this situation.

The ambient pressure difference from corking won't work a clot loose. Blood pressure changes, positional changes, increased pressure in the heart due to gas viscosity and breathing rate are things that could -- which would be side effects of high work rate -- but just going up and down in the water column wouldn't. There's no delta-p in tissues from changes in ambient pressure, everything changes at the same time.

I'm just curious as to the actual current at depth. I think it's quite likely that her body is somewhere in the vicinity however even if neutrally weighted she isn't going to stay at midwater forever for many reasons.

We're all dynamically unstable when neutral and either cork or sink. Once we start to sink, drysuits, undergarments and wings compress and we sink more and become very negative.

 

[MXGratefulDiver]

It was not an unusual current, ocean surge or weather day to visit this site. To arbitrarily post the currents without the reader having a full understanding of the site, current corrections and actually having been there will do no good except cause people to second guess and point fingers. This site and others like it are known for being predictably unpredictable, and that is something people planning on diving it know and accept when working out their margins. I am quite sure that the team understood this, as was indicated by Peter's original post in the other thread.

Something else to keep in mind, this is a site that you can't really know what it going on underwater until you get there.

Case in point, take a look at this video.... Surface conditions would have made me think twice, but once underwater things seem reasonable.

https://youtu.be/VbHT-xyYkB0

Thank you ... not gonna second-guess the boat operator who took them out there. He knows these sites about as well as anyone. You just have to remember, there's a reason they call 'em "predictions" ...

... Bob (Grateful Diver)

 

[Akimbo]

A top-loading washing machine is not a bad analogy for areas like this. It can switch between a gentle filling cycle, agitate, and spin very quickly. A buddy can easily disappear out of sight in seconds without these conditions and much better visibility.

I also wonder if she could have possibly embolized. She apparently went from about 125 or 130 feet to about 70 or 75 feet in a short time, and was actively trying to deal with the ascent when last seen...

Possible, but highly unlikely. Air volume expansion between 130 and 75' is only 0.118 greater. Granted, there is a 1.818 atmosphere pressure change, but the relative expansion is much lower than closer to the surface. Example:

One cubic foot at the following depths would be compressed to:
Surface = 1 Ft³
33' = 0.5 Ft³
66' = 0.333 Ft³
70' = 0.320 Ft³
130' = 0.202 Ft³

I can’t recall an air embolism that didn’t occur in the last 15-20', short of divers in a chamber with a catastrophic hull failure. Does anyone else?

---------- Post added August 30th, 2015 at 09:10 AM ----------

Thank you ... not gonna second-guess the boat operator who took them out there. He knows these sites about as well as anyone. You just have to remember, there's a reason they call 'em "predictions"…

Definitely. There is also a lot of variability in skills and expectations. A great day for divers in the North Atlantic or North Sea would make most recreational divers stay on deck or the dock. Offshore in the PNW (Pacific Northwest) is just as bad, just not as infamous. In fact, very little diving is done outside the Sounds, Bays, and Fjords in the PNW (including Canada and southern Alaska) because the Pacific side is so harsh and unpredictable.

 

[Hatul]

If I were to construct a 'Careful Scale', I would put Lynne quite high on the fanatic side and me about midway between cavalier and mildly astute. In other words, if it could happen to Lynne, then I'm a prime candidate for the caca fan. ...

That was my thinking as well. If it could happen to someone as experienced, knowledgeable and as safety conscious as Lynne it can happen to anyone and myself.

 

[lamont]

Possible, but highly unlikely. Air volume expansion between 130 and 75' is only 0.118 greater. Granted, there is a 1.818 atmosphere pressure change, but the relative expansion is much lower than closer to the surface. Example:

One cubic foot at the following depths would be compressed to:
Surface = 1 Ft³
33' = 0.5 Ft³
66' = 0.333 Ft³
70' = 0.320 Ft³
130' = 0.202 Ft³

0.320 / 0.202 = 1.58 which is a 58% expansion in volume going from 130 to 70 which is more than enough to pop a lung.

EDIT: 4 feet to the surface is enough to cause an injury (12% expansion) which is the same as 82 feet to 70 feet.

 

[Akimbo]

0.320 / 0.202 = 1.58 which is a 58% expansion in volume going from 130 to 70 which is more than enough to pop a lung.

EDIT: 4 feet to the surface is enough to cause an injury (12% expansion) which is the same as 82 feet to 70 feet.

True, but can you understand how a diver would inflate their lungs nearly full at 130' and ascent 55' without exhaling? Remember they were fighting a down-current so both would be have a high respiration rate from exertion. Yes there is about a 50% volume change between those depths but it is over 55', not 16½' like where the vast majority of embolisms occur.

Like I wrote: Possible, but highly unlikely.

Embolism can and does happen to experienced divers in shallow water, like when they get entangled in an out of control lift bag because there is only a short distance and amount of time involved. I never heard of one that occurred deep. It almost happened to me and by some bit of good fortune I was exhaling during the second or two of travel. The full story is somewhere here on Scubaboard.

Edit: I mentioned “inflate their lungs nearly full” because the difference in lung volume between the peak lung inflation during a normal respiration and taking a deep lung-full like a freediver is usually more than twice the volume. A 50% increase over a normal respiratory peak wouldn’t even reach the lung inflation that a freediver leaves the surface with.