Many DH regs are balanced regs, and you can certainly dive them deeper than 130' if you really wanted to. Fact is, none of them perform like modern regs. That's just old diver myth.
Neil
Sea Hunt back on air!!
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Many DH regs are balanced regs, and you can certainly dive them deeper than 130' if you really wanted to. Fact is, none of them perform like modern regs. That's just old diver myth.
Neil
There are both single and two stage double hose regs. They look the same because all the "stuff" is back there in the housing.
The reason DH regs might not breathe as well as single hose regs, at least in a horizontal position, is the pressure differential between the regulator and the mouthpiece. You have to pull the air down from the reg a few inches and through all that corrugated hose. They have to be set just so to breathe well. DH regs breathe like champs when you are vertical! On a single hose reg the second stage is almost at the same level as your lungs so it is easier to breathe from.
Neil
Double hose regs are not quite dead yet. I own both a recently serviced 1961 DA Aquamaster (a two stage double hose reg from US Divers) as well as a US Divers Mistral (a single stage double hose regulator) from the same period.
Some times at the end of a diving weekend I'll trade in the Mk 25 D400's and other modern equipment and play around under the boat with a double hose reg and a horse collar BC. It makes a nice change and is something a little different when the same old thing gets a little boring.
The breathing performnace is not as bad as many people (who mostly have never dove with one) would have you believe and I know the Doria was dove initially with double hose regs. The breathing resistance is higher though than you would accept from any modern reg and this higher breathing resistance can get you into trouble with CO2 buildup. Personally, I have not found any difference in breathing performance between the single and two stage regulators I own and both had their fans. J. Cousteau was a big fan of the Mistral. A few photographers still use double hose regs (although the rebreather now offers even more advantage for photography) and Dacor made a double hose reg on a semi custom, special order basis into the mid 80's.
I agree that breathing performance is largely a matter of adjustment, but then that holds true today with modern single hose regs as well. One of the problems with the double hose reg's reputation as a hard breather may have had to do with their rather rugged design and the fact that they could function several years between servicing although perhaps with less than optimum breathing performance. I noted the other night on sea hunt that one of the divers had a fairly serious leak on the supply side hose where it is clamped to the housing (the area most likely to go bad first). He still was diving it though. Maybe he just did not want Mike to cut a good hose.
There were very few balanced double hose models produced and the Royal Aquamater was the only one I am familiar with. The non-balanced designs breathed a little harder at low tank pressures but then this was handy for giving you some advanced warning of low air pressure. The submersible pressure guage was not commonly used before the mid-late 60's and I still dove with a J-Valve only for a while when I started diving in 1985 due to financial considerations. Believe me, it really sucks when the reg starts breathing hard and you pull the J-valve only to discover it has already been pulled.
But if you want to go play Mike Nelson and relive your favorite Sea Hunt episode it's still an option. There is a vintage scuba industry of sorts with restored regs and other serviceable equipment for sale and a gentle man in England makes new hoses and mouthieces for various models and reproduction buckbill exhaust valves are also available.
Clearing a flooded double hose reg also requires a roll to help drain the water out the exhaust hose rather than just pushing a purge button, so a little training from someone who has dove with one would be advisable and being an expericed diver is almost a must given the different and less user freindly nature of most vintage equipment.
Some times at the end of a diving weekend I'll trade in the Mk 25 D400's and other modern equipment and play around under the boat with a double hose reg and a horse collar BC. It makes a nice change and is something a little different when the same old thing gets a little boring.
The breathing performnace is not as bad as many people (who mostly have never dove with one) would have you believe and I know the Doria was dove initially with double hose regs. The breathing resistance is higher though than you would accept from any modern reg and this higher breathing resistance can get you into trouble with CO2 buildup. Personally, I have not found any difference in breathing performance between the single and two stage regulators I own and both had their fans. J. Cousteau was a big fan of the Mistral. A few photographers still use double hose regs (although the rebreather now offers even more advantage for photography) and Dacor made a double hose reg on a semi custom, special order basis into the mid 80's.
I agree that breathing performance is largely a matter of adjustment, but then that holds true today with modern single hose regs as well. One of the problems with the double hose reg's reputation as a hard breather may have had to do with their rather rugged design and the fact that they could function several years between servicing although perhaps with less than optimum breathing performance. I noted the other night on sea hunt that one of the divers had a fairly serious leak on the supply side hose where it is clamped to the housing (the area most likely to go bad first). He still was diving it though. Maybe he just did not want Mike to cut a good hose.
There were very few balanced double hose models produced and the Royal Aquamater was the only one I am familiar with. The non-balanced designs breathed a little harder at low tank pressures but then this was handy for giving you some advanced warning of low air pressure. The submersible pressure guage was not commonly used before the mid-late 60's and I still dove with a J-Valve only for a while when I started diving in 1985 due to financial considerations. Believe me, it really sucks when the reg starts breathing hard and you pull the J-valve only to discover it has already been pulled.
But if you want to go play Mike Nelson and relive your favorite Sea Hunt episode it's still an option. There is a vintage scuba industry of sorts with restored regs and other serviceable equipment for sale and a gentle man in England makes new hoses and mouthieces for various models and reproduction buckbill exhaust valves are also available.
Clearing a flooded double hose reg also requires a roll to help drain the water out the exhaust hose rather than just pushing a purge button, so a little training from someone who has dove with one would be advisable and being an expericed diver is almost a must given the different and less user freindly nature of most vintage equipment.
