Deep Diving on Air

[waterpirate]

The definition of a "trust me dive" should be added to that advisory.
Eric

 

[DA Aquamaster]

I made hundreds of dives on air below 150 feet, dozens below 200 feet, and several below 300 feet. I started diving in 1972 at the age of fourteen and didn't develop a fear of diving deep on air (the only gas we had until ~1985), it was just another skill set to master. Though now, at the age of 53, I do dive mix below 120 feet.

I started diving 10 years later in the transitional period from air to other gases, but in a region where they were not available. As such I did air to 150' for awhile, but part of the "skillset" was being extremely prudent and ensuring the conditions werewell within carefully defined parameters given the high ENDs involved. Even then, training and proper configuration were key.

The OP's post however suggests none of that and is further indicating a much deeper depth, so it is not a valid comparison at any level.

More importantly with trimix being readily available now, the wisdom of doing deep air is highly questionable and is generallly a bad idea. I'm just not sure I see any value in highlighting an antiquated practice or in presenting it as "just another skillset". People will mis-interpret that, especially if they are not also aware of the fatalities that resulted when air was all their was for deep diving. It's a lot like pointing out that it used to be legal in Montana to drive 100 plus MPH while not wearing a seat belt and with an open container in the car. It may of been legal but it was neither smart nor safe.

 

[knowone]

Geat post a couple of days ago about valve drill training, developing robotic muscle memory in some that have very limited understanding of valve mechanics and therefore adressing a perceived problem in a rigid step form, as opposed to analysing what has occurred and possibly circumventing a step or two and actually adressing the problem, having disseminated the available information with all resources available

Like posts

 

[Culcuhain]

That's one of the problems with narcosis--you usually don't feel it enough to realize what it is doing to you. In her case, she apparently did not realize that she had reached the 300 foot depth and kept going. A buddy caught up with her at 400 feet and turned her around. That extra descent used up their air supply, so they ran out of air at about 200 feet. Fortunately, they had another diver with them who had not gone past 300 feet and who still had enough air to get them to the surface (no stops) with three person buddy breathing. She died. The buddy who caught her at 400 feet is still paralyzed. The other diver will probably recover, although we are not getting reports in him so I can't be sure.

Never become the 2nd casualty.

 

[aquaregia]

Never become the 2nd casualty.

Ever dive with anyone you love? That's an easy statement to ribbit back in a rescue class, but it doesn't always hold up in reality.
YMMV.

 

[DA Aquamaster]

Ever dive with anyone you love? That's an easy statement to ribbit back in a rescue class, but it doesn't always hold up in reality.
YMMV.

Marci and I are a team in every sense if the word, but we are real clear that if things go south, one if us needs to get out of the cave to raise the pre-schooler.

It's a conversation every diving couple needs to have.

 

[Crush]

Marci and I are a team in every sense if the word, but we are real clear that if things go south, one if us needs to get out of the cave to raise the pre-schooler.

It's a conversation every diving couple needs to have.

I hear what you are saying. However, I believe that in caves death can be more black and white than in the case of risky open water dives where shades of gray can prevail. I think aquaregia's post dealt with the latter. I believe that he would risk diving down an extra 100 feet to attempt to rescue a loved one, but would not do so for an insta-buddy. If I have accurately understood him, I agree. I would risk a wheelchair (or worse) to try so haul my kid back up because if I didn't I would not be able to live with myself. That being said, we will not be violating any agency guidelines on depth or exposure, so the odds of me having to chase her down 100 feet are pretty slim.

 

[boulderjohn]

Marci and I are a team in every sense if the word, but we are real clear that if things go south, one if us needs to get out of the cave to raise the pre-schooler.

It's a conversation every diving couple needs to have.

And your last sentence sums up the difference between what you describe and the topic of this thread.

When I did my cave training, I was told that the first step in the lost buddy drill was to check your gas supply and determine how much gas you can budget for your search before you have to save yourself. It is a little bit of a gray area. You might search a little longer and cut your margin a little closer if it is your wife. Every properly trained cave diver has been through this and understands the protocols.

In this thread we are talking about people with no training doing a dive with no protocols. They have agreed to do a dive with someone they love on on one tank of air to 300 feet, a decision that is as close to the opposite of cave diving training as you can possibly get. At 300 feet the beloved just keeps going down, narced out of her mind. Does the diver blithely return to the surface, saying, "Oh, well, good to know you." I think there will instead be a gray area that says that he will go after her for at least a reasonable distance and try to turn her around. What is a reasonable distance? Well, they haven't done the training to make that decision, have they?

 

[Tigerman]

Never become the 2nd casualty.

Ever been in a situation where youve actually needed to make that choice?
I have and I can assure you its not at all as easy or fun to do when in the water as it sounds when youre on dry land. And thats when youve known the person for 3 days...

 

[sddbrown]

Forget Narcosis... Doesn't "air" become toxic below 220 ft? 21%o2 @ 220 = 1.61 PPo2. How are people diving 400 feet on air and not getting a tox hit?