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Post by trapezus on Sept 5, 2016 3:18:26 GMT -8
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Post by surflung on Sept 9, 2016 11:42:02 GMT -8
It is amazing that we beat the Germans when we continue to see so many advanced technologies that they came up with during World War II. It shows the value of a healthy, wealthy economy. Or, as my Dad used to say: "We could have bombed them with Jeeps". We had such amazing wealth and production capacity.
Another aspect of this film that also came to mind when I watched Hans and Lotti Haas movies. They made diving with re-breathers look so easy and fun. We've had it drilled into us about how deadly they were/are that it is kind of strange to see them looking so easy in these old films.
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Post by nikeajax on Sept 9, 2016 12:05:55 GMT -8
Another aspect of this film that also came to mind when I watched Hans and Lotti Haas movies. They made diving with re-breathers look so easy and fun. We've had it drilled into us about how deadly they were/are that it is kind of strange to see them looking so easy in these old films. Eb, with a lot of things, when you see someone who is very well versed in something they make it look easy: that's where the average-Joe gets into trouble, or the infamous last words, "Well h**l, I can do that..."  JB |
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Deleted
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Post by Deleted on Sept 9, 2016 18:18:52 GMT -8
Another aspect of this film that also came to mind when I watched Hans and Lotti Haas movies. They made diving with re-breathers look so easy and fun. We've had it drilled into us about how deadly they were/are that it is kind of strange to see them looking so easy in these old films. It was easy. It still is easy. Re-breathers are not dangerous so much as they are unforgiving of your ignorance. ( I should point out I'm speaking of 02 re-breathers, NOT those floating super computers with a set of rubber lungs on them, commonly used by tech junkies. ) You can pretty much grab any clueless hick off the street and slap an aqua lung on his back and push him under the water. As long as the valve was on and he is breathing.. well, he can have fun blundering around until the air is all gone. Might even have the sense to come to the surface when the breathing gets hard. Not so with a re-breather. Take that same hick off the street and slap a re-breather on his chest and you can have a dead guy in about 5 minutes. He would not even know he died. Was it because the re-breather malfunctioned? Nope. Was it because the hick was clueless. Yup. Hans and Lotti knew there stuff. From what I understand they would dive there 02 re-breathers well beyond 30 feet. How they did that is arcane knowledge. Joe hick would be killed from such lack of knowledge. |
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Post by SeaRat on Sept 11, 2016 22:12:06 GMT -8
One of thos clueless fellows was a young French officer, who tried oxygen rebreather so twice, and convulsed twice. He was using a rebreather he had made, and had no training on them. His name was Jacques Cousteau, and he then turned to developing an open circuit demand breathing system we now call the Aqualung. Concerning Hans and Lottie Hass using their oxygen rebreather at below two atmospheres absolute pressure (33 feet), they definitely had "arcane knowledge." These two divers had literally thousands of dives on their rebreathers, which Hans Hass designed himself. I don't remember where I heard this, but there was at least some speculation that the Hass' did not completely purge their rebreathers of nitrogen from air. In essence, they learned via experience to use mixed gas, without any electronics. I will look at their books (I have two of their books), and will try to see whether Hans mentions this. But if they did use this, it was completely from their diving experience. It must be remembered that Hans Hass had his doctorate in biology, and so may have been able to ascertain methods he would not want to publish to allow the use of his rebreathers at greater depths than allowed by pure oxygen. But without some sort of oxygen indicator, this could have been very hazardous to almost all divers. www.navysealmuseum.org/about-navy-seals/seal-history-the-naval-special-warfare-story/seal-history-origins-of-naval-special-warfare-wwiiI had not seen much about Hitler's underwater swimmers, but I think the manned torpedos were actually Italian inventions. Above is a link to the Navy*SEAL Museum, which talks about the U.S. Navy units that participated in WWII. John |
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Post by surflung on Sept 12, 2016 10:15:40 GMT -8
- I think this is the movie I saw in which Lottie Haas passed out and they had to go and find her. Hard to tell whether or not it was staged for dramatic enhancement. I noticed they're wearing nose plugs under their masks... So not only could they not clear a flooded mask, I would think their masks would be squished in from pressure if they went very deep.
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Post by surflung on Sept 12, 2016 10:47:05 GMT -8
 - Out of respect for the original post, I thought I'd mention I recently saw the Italian divers and their torpedo submarines in "The Silent Enemy". Pretty neat movie with the Brits trying to fight them. |
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Post by SeaRat on Sept 12, 2016 12:25:43 GMT -8
- I think this is the movie I saw in which Lottie Haas passed out and they had to go and find her. Hard to tell whether or not it was staged for dramatic enhancement. I noticed they're wearing nose plugs under their masks... So not only could they not clear a flooded mask, I would think their masks would be squished in from pressure if they went very deep. Surf lung, First , thanks for posting this movie. Please note from the credits that Lottie was, at that time, not yet married to Hans. In his book, "We Came From The Sea," Hans Hass states: Concerning the use of nose clips, they can be applied loosely so as to help with hands-free clearing of the ears, which is especially handy with round or oval masks without nose pockets. I have used nose clips with my underwater swimming experiments, and the neither prevent mask equalization nor clearing of the mask (which Hans Hass stated his team repeatedly practiced in his book). John *Hass, Hans, "We Came From The Sea," (originally published in German as "Wir kommen aus dem Meer"), Doubleday & Company, Inc., 1959, pages 265-266. |
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Deleted
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Post by Deleted on Sept 12, 2016 13:38:47 GMT -8
One of thos clueless fellows was a young French officer, who tried oxygen rebreather so twice, and convulsed twice. He was using a rebreather he had made, and had no training on them. His name was Jacques Cousteau, and he then turned to developing an open circuit demand breathing system we now call the Aqualung. John I've read the more detailed account of his two experiences. I think he was on the ship Suffren ( going off memory as the book is packed away.) and it was a gunner's mate that built it for him. The first dive did not go well though the experience of a more true silent world was captivating. He made changes in the design in an attempt to fix issues that had little to do with the problems. Dive 2 was cutting it close to fatal. Anyhow I often wonder what would have happened if he did have a better understanding of breathing high PP02 at depth. |
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Post by surflung on Sept 12, 2016 14:08:25 GMT -8
Concerning the use of nose clips, they can be applied loosely so as to help with hands-free clearing of the ears, which is especially handy with round or oval masks without nose pockets. I have used nose clips with my underwater swimming experiments, and the neither prevent mask equalization nor clearing of the mask (which Hans Hass stated his team repeatedly practiced in his book). John *Hass, Hans, "We Came From The Sea," (originally published in German as "Wir kommen aus dem Meer"), Doubleday & Company, Inc., 1959, pages 265-266. - Thank you for that.. Looks like I'm going to have to give that a try!  |
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Post by nikeajax on Sept 12, 2016 16:03:10 GMT -8
Concerning the use of nose clips, they can be applied loosely so as to help with hands-free clearing of the ears, which is especially handy with round or oval masks without nose pockets. I have used nose clips with my underwater swimming experiments, and the neither prevent mask equalization nor clearing of the mask (which Hans Hass stated his team repeatedly practiced in his book). John *Hass, Hans, "We Came From The Sea," (originally published in German as "Wir kommen aus dem Meer"), Doubleday & Company, Inc., 1959, pages 265-266. - Thank you for that.. Looks like I'm going to have to give that a try! This little exchange is exactly why our site is so good: ZERO attitude, and no one snarling, "Well... I guess the search button isn't working at the moment!" JB |
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dman
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Post by dman on Sept 25, 2016 14:52:47 GMT -8
People have different tolerance to O2
Which is why military does O2 tolerance tests to determine how deep can go before passing out
Used to weed out those with poor tolerance to O2
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Deleted
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Post by Deleted on Sept 26, 2016 4:49:07 GMT -8
From the National library of medicine:
The United States Naval Special Warfare Community uses oxygen tolerance testing to screen Navy combat swimmer candidates for sensitivity to the toxic effects of hyperbaric oxygen (HBO2). Between 1976 and 1997, 6,250 oxygen-tolerance tests were performed at the Naval Special Warfare Center and Naval Special Warfare Group One. Our review of these data found only six episodes of O2 toxicity for an incidence of 0.096%, an incidence considerably lower than the rate of 1.9% reported in an earlier review using data from the Naval Safety Center. Additionally, we reviewed data from the Naval Safety Center from 1986 to 1997 and found only one episode of O2 toxicity among 157,930 LAR V dives. Many factors other than individual sensitivity to HBO2 may contribute to the occurrence of O2 toxicity episodes during combat swimmer operations. The authors conclude that O2 tolerance testing of U. S. Navy SEAL candidates is not a useful screening test and recommend discontinuation of this test.
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Post by nikeajax on Sept 26, 2016 8:06:54 GMT -8
Dman, thank you for bring that issue up: Cstmwrks, thank you clarifying  I'll stick to open-circuit-systems, scuba: there's already way too much to think about during a dive  JB |
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Deleted
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Post by Deleted on Sept 26, 2016 9:52:19 GMT -8
I'll stick to open-circuit-systems JB I have no love of, or desire for those computer driven deep diving rebreathers, Just like I have no desire for deep OC trimix or any other brewed gas. Dangling from a line with 6 over pressured 120's just does not sound fun. Not even a little. I like the zone from 0 to about 50 feet. When I was in Alaska the fun tended to vanish after 60 feet. The bay that I went to most was pretty much a gravel pit past 60 feet. 104 was as deep as I've explored looking to see if some miracle swath of life would pop out. Seemed safe to bet that the 300 to 400 foot deep parts would be about the same. Anyhow an 02 system is simple and compact. I can enjoy the "zone" and pound for pound of dive gear I can have 4 times the duration underwater. I can back pack into remote super clear lakes that tend to be less that 30 feet deep and carry what is needed on my back. Chirpa's not needed. OK.. take that back. Yes. They are needed. Some one has to pack in the espresso machine and generator! |
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I'll stick to open-circuit-systems, scuba: there's already way too much to think about during a dive 
