Yukon tangent thread

[lamont]

@lamont: You've made a lot of assumptions in your assessment.

All of which are perfectly rational based on every single boat dive that I've been on, and based on the fact that the Yukon is largely square-profile.

You'd have to make wild assumptions about bizzare profiles or SAC rates or him going down right as most everyone else is coming back from their dive to arrive at a situation where even the most attentive boat would have had half a chance to rescue him.

Roll calls and generally people on the boat cannot possibly save you or anyone else who runs out of gas on the bottom.

 

[divemaster dave]

It's reasonable to think that if the diver did not surface in trouble (and it's reasonable to think he did not, with another boat on site that could have seen him if he did)

I would like to know what other boats were there at the Yukon besides going by local schedules. When the Humboldt left there was no one else sitting there.

I saw about a 15-20 minute time period where there were no boats there at all.

 

[Bubbletrubble]

I have taken numerous Advanced Open Water students to 100 feet for their first time (many of them at the Yukon). I have never seen anyone noticeably impaired by narcosis at that depth. It's unusual for them to even notice any effects. While nitrogen narcosis does occur at 100 and shallower, it is usually too mild to notice.

@Scot M: How are you assessing the presence of narcosis? The fact that you have never observed narcosis in your students at a depth of 100 fsw implies you are not testing for it properly. Please consider task-loading your students in novel ways at depth. Most instructors have their AOW students open a combination lock or work a math problem at depth. In most cases, such an exercise will not reveal any deficits.

Did anyone from the San Diego area see the channel 10 news at 11:00 last night? they interviewed the owner of the Humboldt. He had some interesting things to say. He also seemed to know Mr. Clampit (sp) from previous trips on the boat. His impression was that he was a more than competent diver. He also had a few comments about the lack of a proper head count and how that made his organization look.

I watched it. Here's a link to the article on the Channel 10 website that contains a video clip:
Boat Owner Discusses Fatal Diving Accident - San Diego News Story - KGTV San Diego

I feel bad because I know and like the person who was captaining the boat at the time. She is a very safety-conscious individual. I don't know the DM, though.

An experienced deep diver at 100 feet should be able to manage narcosis effectively, and it really should not become a factor unless the diver runs into a problem and is less effective than needed in solving it.

The only way breathing gas would have affected this would be if he was breathing a helium mix to reduce the amount of narcotic gases being breathed. Divers usually mix helium so that it gives an equivalent narcotic depth of 100 feet, so I sincerely doubt he would have been breathing a mix that would have given him any benefit.

Well said, boulderjohn. A lot of newbie divers think that narcosis is greatly diminished by diving nitrox. This notion is based on the incorrect assumption that only the nitrogen in breathing gas has narcotic effects.

It's interesting that this guy was a local diver, doing a fairly deep dive, and he chose to use an AL80 tank filled with air. Most of the experienced local divers I know would take a lot more than 77.4 cubic ft. of gas with them on a Yukon dive, particularly if they were planning to photograph stuff on the sand. Most would agree that a 32% nitrox mix would be preferable for a Yukon dive. It makes me think that: (1) the victim probably wasn't that experienced and (2) he wasn't a very serious photographer. I'm curious how many solo dives he had conducted prior to the incident.

All of which are perfectly rational based on every single boat dive that I've been on, and based on the fact that the Yukon is largely square-profile.

Without exception, on all of my Yukon dives, I have adopted a multilevel profile. I know that I'm not alone on this.

Understand that I'm not saying the Humboldt crew had a high probability of helping out the victim even if the boat had remained on site.

 

[divemaster dave]

Very sad but oh so preventable.

Your bubble watching comments border on the absurd, after all at 105 on an AL80 he could have well been dead while other divers were in the water, oh yea, making bubbles. Oh yea, what does the boat do when there are multilpe boats on the Yukon at the same time (Very common situation here in San Diego), do the boats need to somehow color code the bubbles so they can track which divers the bubbles they are tracking are coming from?

At this time the Humboldt was the only boat on the Yukon. It is very easy to watch a diver traverse the Yukon especially if there was just one left. Clampitt was the only diver in the water before they left. You can easily tell the difference between steady streaming purges form a reg and the sporatic leaking from bubbles trapped inside. I have done this hundreds of time. It is common practice on wrecks and in the kelp here.

 

[Thalassamania]

The only purpose that a head/tank/other count serves is to make sure that no divers are left behind in the water when the boat leaves, a situation that could range from the inconvenient to the fatal, depending on the circumstances. The idea that a count would be the spark to ignite a useful and successful rescue of an OOA diver who is unconscious on the bottom at 100 feet is nonsense.

 

[Adobo]

Edit: Let me try to be more constructive about this...

At this time the Humboldt was the only boat on the Yukon. It is very easy to watch a diver traverse the Yukon especially if there was just one left. Clampitt was the only diver in the water before they left. You can easily tell the difference between steady streaming purges form a reg and the sporatic leaking from bubbles trapped inside. I have done this hundreds of time. It is common practice on wrecks and in the kelp here.

Okay, for my benefit, can you walk through this scenario? Assuming the boat crew has someone trailing the stream of bubbles for this guy. Now lets say the bubbles stop (clock starts ticking. Actually, the clock started ticking maybe a minute or two ago since the last bubbles that you see at the surface were exhaled at depth and had to travel 100ft to the surface.). Can you walk me through the sequence of events by which this diver would have been successfully rescued? Please include the amount of time necessary for each step.

 

[Thalassamania]

The problem is that screwing up the count and leaving the sight impeaches the creditability of the boat crew and its operations. It makes it easier to make the jump to the idea that they did something (as yet undiscovered) that was wrong and that contributed to the diver's death. Clearly this is an unwarranted logical jump, but it occurs just the same.

 

[lamont]

Without exception, on all of my Yukon dives, I have adopted a multilevel profile. I know that I'm not alone on this.

Is there a lot to see above 30 feet on that dive?

 

[Scot M]

@Scot M: How are you assessing the presence of narcosis? The fact that you have never observed narcosis in your students at a depth of 100 fsw implies you are not testing for it properly. Please consider task-loading your students in novel ways at depth. Most instructors have their AOW students open a combination lock or work a math problem at depth. In most cases, such an exercise will not reveal any deficits.

In my previous post I acknowledged that nitrogen narcosis occurs at 100 feet and shallower. Testing under controlled circumstances or with experienced divers can show this clearly. An AOW class on their first deep dive in the open ocean is not, however, a sufficiently controlled setting. The mild narcosis most people experience at 100 feet is easily masked by stress, cold, water movement, familiarity, or other factors. I have tried a variety of different tests (puzzles, math problems, word puzzles, mental games, etc.) but none of them has demonstrated a repeatable outcome that was clearly attributable to narcosis. I was pleased when that particular waste of time was removed from my agency's AOW standards.

 

[divemaster dave]

Edit: Let me try to be more constructive about this...



Okay, for my benefit, can you walk through this scenario? Assuming the boat crew has someone trailing the stream of bubbles for this guy. Now lets say the bubbles stop (clock starts ticking). Can you walk me through the sequence of events by which this diver would have been successfully rescued? Please include the amount of time necessary for each step.

Yes I was a county PSD Diver and could run you through the steps. But it's not even worth the time it takes to type and try and explain it to you. Because I can already see your response to that. He was brain dead anyway, right?

The point that I am trying to make is that one, they first couldn't figure out he was overdue. Meaning that someone can't squeeze 2 hours out of an AL80 at 100 feet. The other point is that they left. Meaning they could have afforded his the respect of an immediate retrieval from the bottom, attempted resuscitation sooner than 1.5 hours after death and notified the USCG in a timely manner, instead of diving another dive site and completely forgetting about him.

That's all. Whether or not he had a chance at resuscitation, whether or not you blame him entirely for his own death doesn't make a difference. He should have been afforded the opportunity and the respect of an attempt. But that would have been done by one of the other dive boats arriving at the Yukon, not the Humboldt.