Learned Wrong...

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Ascent procedure was 60 fpm all the way to the surface. That's now considered "wrong" by most.
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[Thalassamania]

It is?

 

[Akimbo]

Papa T often did that which is impossible today ... he just forgot to ask.

View attachment 109300
Dr. George Bond and Chief Engineman Cyril Tuckfield following record buoyant ascent in 1959, indicating that they are in trouble and in need of rescue.

Captian Bond was one of my heroes. The more I learn about him the more the admiration grows. I was very lucky to know Tuck.

That photo reminded me of one of the great experiences of my life, I just wish I was smart enough to realize it at the time. Chief Cyril Tuckfield was nearing retirement when I was assigned to Submarine Development Group One. Tuck was running the dive locker housed in the repurposed gun emplacements at the end of Pt. Loma in San Diego.

After hours I would walk over from the enlisted quarters and prompt him for stories of his days on submarines during WWII through the Sea Lab Programs. I should have been taking notes because he lived more history than I have time to read. We had three Saturation Qualified Master Divers onboard (a really big deal in those days). They all treated Tuck with a level of respect rarely seen outside their elite circle. I regret not having the insight to understand what a humble and accomplished guy he was. He taught me more than I can verbalize.

 

[Thalassamania]

You're one lucky dog.

My connection to Navy sat was through Bob Barth, and like you, I was too entranced with the sea stories to take notes.


Note that Bob and Scott Carpenter are also in distress and need of assistance.

 

[VooDooGasMan]

There gear bag(goodie bag) looks the same as the one I still use. How can you learn wrong, nothing really has changed that much in all these years.

 

[BluewaterSail]

Going back to the original question.....

The regulator that you donate to an OOA diver must be found in the "triangle" because the OOA diver may not be able to find the regulator if it is in your mouth. Therefore a long hose donate from the mouth is an unsafe practice and should be avoided.

BP/W is much too complicated for a new diver

BP/W is only for technical divers

 

[Diogenesdemar]

Well ... we're all gonna die. Air is a lethal gas ... breathing it results in a 100% fatality rate ...

... Bob (Grateful Diver)

Right. But, then again not breathing it has a fairly high mortatlity rate too . . .

 

[Blue Sparkle]

I’m confused. Are you describing what I know as a pull dump...

Hi Akimbo,

When I said "rear dump," I meant the type with a string that is also an OPV. It was on the lower left corner.

The inflator was the type with which you can vent air by pushing a button and positioning it higher than the BC's air (but not by pulling on it).

I have the same two options on my own BC as were on the rental; difference being that in OW class I couldn't "find" the rear dump on the rental and the instructor said "oh that's because the rental version doesn't have one; you have to use the inflator." He was wrong -- hence my "learned wrong" contribution

I hope that clarifies,
Blue Sparkle

 

[Deep South Divers]

Sorry, I missed this earlier:



We must be using different references: U.S. Navy Diving Manual, Revision 6, 15 April 2008, Page 7-38:

Wow... That's very interesting. I have a copy of Revision 4, dated 1999. It mirrors what you found.

What's most interesting about that is that clearly, the Navy Manual has taken it on their own to redefine certain terms. For example, a "free ascent" is simply an ascent made without a downline or anchor line. Clearly, according to the Navy Manual, it is defined differently.

A "Controlled Emergency Swimming Ascent" (also called an "emergency swimming ascent"), is swimming up in an emergency. It's so commonly defined this way that it's on Wikipedia: Controlled emergency swimming ascent - Wikipedia, the free encyclopedia As far as I know, all agencies from scientific, recreational, and commercial sectors define a "Controlled Emergency Swimming Ascent" the same way, and it does not involve dropping weights: controlled emergency swimming ascent - Google Search It's also called a "CESA" and "ESA" in some circles.

What the US Navy is defining as an "emergency free-ascent" is actually the same thing as what everyone else is calling a "bouyant ascent," where you drop your weights at depth, and no organization that I know of, other than the US Navy apparently, recommends the procedure... The most cited reasons are because swimming is faster than a buoyant ascent, dropping weights generally takes additional time, and because the ascent can be controlled if it's swum, whereas a bouyant ascent can not, especially as the surface is approached. Presumably, a swimming ascent is also at a constant or near-constant speed, whereas a bouyant ascent accelerates toward the surface - the opposite of what is healthy physiologically.

I am surprised to see that the US Navy dive manual recommends dropping weights at depth. I haven't seen any organization recommend that over a CESA.

Then again, it also surprises me that they recommend inflating a "life preserver" at depth in addition to dropping weights... Again, in opposition of what I see every other organization recommend.

They also recommend cutting off the necklace from necklaced backups, and, when rescuing another diver, to make that person very bouyant and then "maintain contact" with them... In other words, shoot your buddy to the surface, and hold onto him while he rockets to the surface.

These things are in direct opposition with what is taught by many agencies, the latter part is direct opposition to a PADI Rescue class, for example.

It is derived from the earlier use of the term in submarine escape. Those ascents were generally buoyant, though not necessarily, and ideally very rapid — 300-600’/Min.

I figured.

I don't know if a submarine is kept at 1 ATA while submerged, but if it is, that would make sense physiologically. Personnel escaping a sub, therefore, would take a breath, "blow" the hatch, and then immediately attempt as fast an ascent as possible. In this way, they're more like freedivers, and lung overexpansion and DCS are nonissues because they are not breathing compressed gasses at depth.

In other words, the physiology of a diver and a submariner are distinctly different because of the exposure to ambient pressure at depth. The idea of a bouyant "emergency free-ascent" makes sense for an escaping submariner. It does not make sense for a diver OOA.

I suspect that the differences were either unknown or mistaken when the US Navy manual was created and therefore flawed.

Sidebar: Captain George Bond, the father of saturation diving, made a record free ascent from the submarine USS Archerfish from a depth of 363' in 1959. It hardly seems like a big deal today where freedivers make the round-trip on one breath deeper than that. But it was a huge accomplishment at that point in the understanding of the diver physiology.

That doesn't seem like it sheds light in terms of "diver physiology" to me, unless, of course, Captain Bond was breathing gasses at an ambient pressure of 12 ATAs first. If he simply went from 1 ATA to 12 instantly, then either swam or made himself bouyant to travel - successfully - 363' to the surface to 1 ATA again, his profile much more closely resembled a freediver on a single breath hold than that of a scuba diver, with dissolved gasses in his tissues. The two physiologies are almost totally unrelated.

A scuba diver doing this kind of ascent - that is, becoming buoyant through the dropping of weights and/or the inflation of a "life preserver" (BC) - and traveling as quickly as possible from 363' to the surface - would clearly be an exceedinly dangerous thing to do. This type of profile would almost certainly result in severe (and possibly fatal) DCS, and likely create all kinds of barotrauma for a scuba diver, such as an anneurism.

The part I find interesting is most “modern” Scuba instructors believe it is impossible for some reason.

I don't know that they believe it "impossible" so much as they feel that it is not a healthy, positive solution to a problem at depth.

 

[Thalassamania]

The record for submarine escape now is 601 feet using an escape suit.

Subs are at 1 ata, more or less. The submariner enters a lock and is sealed in, it is rapidly flooded to equilibrate pressure with the water outside. The submariner opens the hatch (or the now compressed air blows it open when the pressure equalizes) and the submariner exits and rockets to the surface. This is done wearing a suit that covers the entire body. The submariner breathes normally, all the way to the surface.

Submarine Escape and Rescue Training