dogfix
Regular Diver
Posts: 13
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Post by dogfix on Mar 30, 2004 10:54:09 GMT -8
Does anyone have a copy of the service manual for the Waterlung Sport-Divers? Mine are from the late '50s to early '60s.
I finally got my DA Aquamaster wet. Took it to a pool dive with the local dive club. They rented time in a 16' deep pool. Spent an hour and a half in the water, playing water games. It performed flawlessly.
Time to get it into the big lakes. A question just occurred to me: How does the DA Auqamaster handle cold water? Is there a freezing/ice forming issue? Not that I'm planning on doing an Ice Dive, I'm just curious.
When diving with a double hose how do you position your snorkel? Best place I found was in my pocket.
Thanks!
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Post by SeaRat on Mar 30, 2004 20:57:14 GMT -8
When the jet didn't make the takeoff and crashed through the ice and into the Potomac River in Washington, DC in the 1980's, the US Navy was sent to search for the cockpit recorder and other stuff. They started out with Uni-Suits and Poisiden regulators. They immediately tore large holes in their suits, and had freeze-up problems with their new regs. They switched to wet suits and double tanks with DA Aquamaster regulators. The DA Aquamaster is almost immune to regulator freeze-up. They were used in the Antarctic, and coated with ice, without freeze-up problems (provided dry air is used). You won't have any problems with a DA Aquamaster in cold water, especially a lake.
I wore my snorkel (which is attached to a bicycle helmet that I wear too) last Sunday while diving my Trieste II, and I wear it inside the left exhalation hose. There is no problem whatsoever doing that.
John
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Post by caveman on Apr 4, 2004 12:45:13 GMT -8
I have heard that is the case with other double hose regs. Is that true?
caveman
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Post by SeaRat on Apr 4, 2004 16:52:43 GMT -8
Caveman,
Yes, it is true of many double hose regulators, but not all of them. The DA Aquamaster, Royal Aquamaster, and Mistral all have their mechanisms inside the case, and basically subjected only to air, and not the ambient water. The Mistral, being a single stage regulator, would potentially got colder on the outside due to the rapid drop in pressure, but the mechanism is still inside.
For the Aquamasters, both the first stage mechanism and the second stage are inside the regulator, where there is only air present. Because of this, ice can build up on the outside of the case, usually on the first stage on the back of the case, and it will not interfere with the functioning of the regulator.
Other double hose regulators are not quite so impervious to freeze-up. My Sportsways Hydro Twin, for instance, has the first stage outside, subjected to the water directly. But the second stage would be protected. This could cause first stage freeze-up, but so far has never happened to me.
The Snark III has an overpressure relief valve is subjected directly to the water. It is therefore possible for that to freeze up, and potentially cause a safety problem if there were a malfunction of the first stage.
Double hose regulators separate the second stage mechanism from water vapor from the mouth too, by use of the mouthpiece non-return valves and the general flow of air through the right hose to the diver, and exhalations through the left hose. So second stage freeze-up is not much of a problem for double hose regulators.
John
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