Yukon tangent thread

[Jax]

Empty tanks. Generally people who go into cardiac arrest stop breathing.

How do you know the tank was empty? Source, please.

 

[Jax]

I was on the Humboldt yesterday during the mishap. It was great dive conditions. 30 ft of viz, almost no surge. The bottom was at 110ft. The diver that died was using an aluminum 80 on air and was diving by himself. When his body was recovered he had no air left in his tank. The diver seemed intent on photography and was last seen some feet away from the Yukon looking at something in the sand.

This is the ONLY place I have seen that says "there was no air left in his tank". However, the Humboldt AFAIK did not return to the scene. How would people on the Humboldt know about air in the diver's tank?

 

[divemaster dave]

Yes, tell us again how you ascended from a 100ft dive, detected a perceived problem, and then descended back to 100fsw with a fresh tank to resupply your friend who apparently believed that 100fsw was a good place for a 35 minute decompression stop. Did you do this on your original AL80, or did you change out tanks for yourself too. What mix were you breathing? Didn't you have a deco obligation too, or did you bounce down, switch out regulators and do a rapid ascent???

If you're dead, you probably won't feel too bad about it.

There you go assuming again. This just wastes everyone's time trying to straighten out your speculation and harassing claims. I had double 130's, and an AL80. His dive computer gave bad reading that he didn't want to violate. He should have beaten me to the surface since he had a shorter run time. He didn't. I went looking for him and brought my AL80 that was almost full. I found him at 100' when, he was not doing deco there. (about your 10th ignorant assumption here) we ascended together from there and I rode out the rest of the dive with him.

I had completed my deco. Mix is irrelevant. Sounds like you need to take some more classes. I am not in the business of teaching internet classes.

Can you live with any of this or do you need my dive log, dive computer, perhaps some references from a dive training manual and witness statements? It was a simple rescue in my book and all of it has value and could have been used with the Humboldt scenario.

 

[Jax]

fftopic:

There you go assuming again. This just wastes everyone's time trying to straighten out your speculation and harassing claims. I had double 130's, and an AL80. His dive computer gave bad reading that he didn't want to violate. He should have beaten me to the surface since he had a shorter run time. He didn't. I went looking for him and brought my AL80 that was almost full. I found him at 100' when, he was not doing deco there. (about your 10th ignorant assumption here) we ascended together from there and I rode out the rest of the dive with him.

I had completed my deco. Mix is irrelevant. Sounds like you need to take some more classes. I am not in the business of teaching internet classes.

Can you live with any of this or do you need my dive log, dive computer, perhaps some references from a dive training manual and witness statements? It was a simple rescue in my book and all of it has value and could have been used with the Humboldt scenario.

Would you get off yourself and stick to topic? That nonsense is unneccessary and unappreciated.

 

[Scot M]

@Scot M: I see that you are a PADI instructor. I'm not sure how you were testing for narcosis previously.

Most of the local dive instructors I know ask the AOW students to perform a task on the surface and then have them do the same task underwater at 90-100 fsw. The problem with doing this is that the student is expecting it (mentally preparing for it/focusing on it)...and it doesn't control for learning.
I'd recommend having the student look at a number or series of numbers, do a novel math problem, work a word puzzle, and then recall the number/series of numbers. Compare this later on to the student's performance of similar tasks topside. One effect that many observe with narcosis is that it tends to narrow one's focus. Tasks take longer to perform and take a performance hit in accuracy. Task-loading is a fairly reliable way to reveal cognitive deficits due to narcosis. Try it if your agency's teaching standards allow for it. You'll be surprised by the results.

Like I said, I've tried a variety of tasks such as you suggest. These have included putting together puzzles, solving medium difficulty multiplication problems, or writing a phrase backward. I have tried it with the surface trial first and with the deep trial first. I have tried it with the surface trial in the water and out of the water. A significant percentage of AOW students do these tasks faster at depth simply because they are more focused. Others have trouble at depth but cite specific causes such as numb fingers or dim ambient light.

I came to the conclusion that other factors than nitrogen narcosis play a far bigger role in the performance of inexperienced divers at 100 feet. PADI evidently came to the same conclusion, because the narcosis demonstration was removed from the AOW course last year and replaced with an observation of color changes. The narcosis test is now only required in dive 3 of the deep specialty, which is usually a 130-foot dive.

I am absolutely unconvinced that nitrogen narcosis could have played a role in the accident except (and this is a big exception) possibly contributing somewhat to a lack of situational awareness.

 

[Bubbletrubble]

Even with a rate of 0.30 CF/min he's still dead before the boat leaves, still dead before anyone can get to him.

Am I missing something here? Could someone please set forth the timeline of events in an unambiguous manner? Based on the information released, it's unclear to me when the diver started his dive, when the boat left the dive site, and when rescue/search attempts began.

To get the kind of outcome you are looking for he would have needed to spend considerable time on a non-square profile, which means floating around at 30 feet or less. If he was on the line he would have been seen. Which means that you've got a hypothetical diver in midwater floating around off the line at 30 feet for times on the order of 30 mins while he slowly drains his tanks and the boat leaves. I seriously doubt it.

Honestly, I'm not looking for any outcome at all. I'm just stating a possibility given the facts that we have to work with.
Doubting something and acknowledging that a scenario is possible but not probable are not necessarily mutually exclusive.

Empty tanks. Generally people who go into cardiac arrest stop breathing.

You realize that it's possible for a heart attack to occur without complete, permanent cardiac arrest, right?
If you're trying to make the point that an empty tank argues against a medical condition contributing to the incident, you are sorely mistaken.

I am absolutely unconvinced that nitrogen narcosis could have played a role in the accident except (and this is a big exception) possibly contributing somewhat to a lack of situational awareness.

@Scot M: Lack of situational awareness or demonstration of poor decision-making at depth are possible effects of narcosis.

 

[divemaster dave]

This is the ONLY place I have seen that says "there was no air left in his tank". However, the Humboldt AFAIK did not return to the scene. How would people on the Humboldt know about air in the diver's tank?

This guy needs to stop calling the shots from the high desert 8 hours from San Diego, especially since you have no direct knowledge of the incident and others here do.

The Humboldt did return to the Yukon. Called MAYDAY on the radio and initiated the emergency response, although an hour too late. The LG reported to the Humboldt crew and owners that the tank was empty.

Please list your source where you claim that they did not return to the Yukon? How do you know this? You must have good binoculars.

 

[Thalassamania]

1. I'd have trouble confusing Jax with a guy.
2. The Humboldt did return to the Yukon. Called MAYDAY on the radio and initiated the emergency response, [-]although an hour too late[/-] an hour later than they might have. It is unlikely that this error on their part, however, had any effect on the outcome of the accident.

All you needed to say was, "The LG reported to the Humboldt crew and owners that the tank was empty."

 

[divemaster dave]

fftopic:


Would you get off yourself and stick to topic? That nonsense is unneccessary and unappreciated.

Read back, it is on topic. People asked for me to give and example of a rescue that could have helped. I just so happened to have a real example of one of mine. If you can't see the value in it then ignore it and move on.

 

[Scot M]

Where did this alleged hour delay come from? The only mention of an hour that I remember in any of the first hand accounts was the lifeguards saying that the victim had been underwater for an hour.