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Post by nikeajax on Feb 20, 2018 11:06:13 GMT -8
Phil, I agree with you totally! JB
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Post by SeaRat on Feb 20, 2018 12:26:47 GMT -8
Phil, I actually did not bring the argument to this forum; I simply copied one reply I made that was pertinent to our discussion here, but linked it to the conversation on Facebook. I did reply to that person who disagreed with me about teaching buoyancy from day one, which I could include here, but it was more pertinent to that other discussion than here. I posted this image earlier, but I want to explain it a bit more. I'm wearing a USAF issued wet suit top, to which I cut off the arms. It is a 1/8 inch neoprene top, meant for warm water. I cut the arms off because they were not necessary, and actually impeded some of my movements, both in a parachute and in the water. I am not wearing a weight belt in this photo. That is because there was no need, as the neoprene did not really float much. So there was virtually no loss of buoyancy as I dived, and this part of Alexander Springs got to a max depth of maybe 25 feet. The other part of this is that without a BCD, the diver is free to move without the resistance that a vest or even a back-mounted BCD gives. It is a much freer way of underwater swimming. John
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Post by Aquala1 on Mar 6, 2018 21:10:24 GMT -8
I guess I’ll jump in here since it has a bit to do with drysuits. When I was first taught drysuit diving, I was taught to use the suit for buoyancy control, and the BC for surface flotation. When using a single AL80 for the training dives, this worked fine. I was properly weighted, and we verified proper weighting by whether we could hold neutral at 15 feet with virtually an empty tank (500psi) and no air in the suit, or BC.
The problem with using this method for me, came when I started using twin 3000psi + rated steel 80s. I didn’t have to add auxiliary weight, because the tanks were heavy enough on their own. However, they were so heavy that by trying to use only the suit as inflation, the suit became unmanageable. There was too much air shift when changing depth. Head slightly down, and it would all rush to my legs and feet. Slightly head up put so much air at the neckseal that I could barely move my head.
After one or two dives like that, I knew there had to be a better way. After doing more research, it was suggested that for these heavy tanks, you use the BC/wing to offset the tanks negativity, and dive just enough air in the suit to take the squeeze off the chest. Yes you’re managing two air cells, but the one in the suit is minimal and with automatic exhaust valves, almost mindless in their function. You slightly raise your shoulder, and the excess air escapes. With a wing while horizontal in the water, you pull the rear dump valve to vent and to regain neutrality. It’s two quick motions (raise shoulder, tug rear dump) and neutrality is good to go. With practice, both moves almost become one and it really is effortless.
I’m not saying this is right for everyone, but that’s what’s worked for me.
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Post by crabbyjim on Mar 12, 2018 5:55:11 GMT -8
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Post by SeaRat on Mar 12, 2018 7:55:47 GMT -8
No, just looking at the clip, I think that was actually Lloyd Bridges and Zale Parry. John
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Post by nikeajax on Mar 12, 2018 9:07:23 GMT -8
Homey don't play Face Book, so I'll just have to pretend I saw it... If I remember correctly, it was Zale Parry and Dick Anderson who taught Mr. Bridges the fine art of diving JB
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Post by Aquala1 on Mar 12, 2018 13:45:05 GMT -8
Cool clip, but I still don’t see why they dove with weight belts when not wearing wetsuits. The steel tanks are heavy enough. This was a question I posted a while back, before I had assembled my vintage rig. After getting an original 1959 USD tank set w/ canvas harness, I tried the rig out in the pool with only a DA Aquamaster, mask, trunks, and pair of Churchills. I was still heavy.
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Post by nikeajax on Mar 12, 2018 14:45:18 GMT -8
Ty, have you seen "The Mermaids of Tiburon"? The hero never used weights with his kit either, just shorts, mask, fins, tank and reg. BTW it was filmed at both the Channel Islands, in southern California USA, and Loreto, Baja California Sur, Mexico. And then there's Dinne Webber, umm-ahhh, holy mother of pearl: warning she'll give ya high blood pressure just lookin' at her! Just do an image search and you'll understand--SIGH!
JB
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Post by crabbyjim on Mar 12, 2018 15:22:00 GMT -8
Cool clip, but I still don’t see why they dove with weight belts when not wearing wetsuits. The steel tanks are heavy enough. This was a question I posted a while back, before I had assembled my vintage rig. After getting an original 1959 USD tank set w/ canvas harness, I tried the rig out in the pool with only a DA Aquamaster, mask, trunks, and pair of Churchills. I was still heavy. Just a guess but I suspect that the film makers wanted them on the bottom and didn’t make the shot in one take. I posted it to show divers on the bottom, which is where we were unless we were actively swimming because we couldn’t adjust our buoyancy. Searat’s videos of himself in the pool in vintage gear with no wetsuit show him on the bottom unless he is using one of his swimming devices.
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Post by Deleted on Mar 12, 2018 15:26:17 GMT -8
Cool clip, but I still don’t see why they dove with weight belts when not wearing wetsuits. The steel tanks are heavy enough. This was a question I posted a while back, before I had assembled my vintage rig. After getting an original 1959 USD tank set w/ canvas harness, I tried the rig out in the pool with only a DA Aquamaster, mask, trunks, and pair of Churchills. I was still heavy. Just a guess but I suspect that the film makers wanted them on the bottom and didn’t make the shot in one take. I posted it to show divers on the bottom, which is where we were unless we were actively swimming because we couldn’t adjust our buoyancy. Searat’s videos of himself in the pool in vintage gear with no wetsuit show him on the bottom unless he is using one of his swimming devices. It was a movie. Maybe for special effects the weights were nothing more than plastic for authentic looks? Then again women are more buoyant than men for obvious reasons. Mike? Who knows, my twin 38's are buoyant but I've never used weights diving in just a swim suit, because they are Not that buoyant. But that was fresh water also. Those looked like no more than one or two lbs weights.......couldn't tell how many she or he were wearing. And she was pushing herself off the bottom......so they were over weighted.
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Post by nikeajax on Mar 12, 2018 15:26:51 GMT -8
One of the things we learned is that The Sea of Cortez is 25% more saline than the Pacific Ocean: yer gunna be way more buoyant in it!
JB
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