depth limit

[john]

I am a certified diver interested in two hose regulators, and i have a few questions. 1. What is the depth limit of 2 hose regs? and is it possible to turn off the second stage during free flow?

[john]

also can you use 2 hosers with yoke valves

[nemrod]

John, I am not the expert and I am not clear on your questions. Double hose regulators are not depth limitied per say and should be good for typical sport diving down to 130 feet or so. The Royal AquaMaster, at least my two, perform on par with most modern mid range regulators and even as good as a certain darling of the Tech crowd from my small knowledge of that particular unit.
All double hose regulators that I am aware of were designed for Yoke Valves---not DIN---and most prefer less than 2500 psi though the Royal, DA, Trieste etc can operate well on 3,000 psi. The Mistral I would not use beyond 2400 or so psi.

No, you cannot turn the "second" stage off, there is no purge valve or external adjustments. There are no conventional provisions for an spg and octapus either but there are adaptors that allow these functions to be accomodated.

Further, and please don't take this the wrong way, modern dive instruction is inadequate for diving with double hose regulators, the methods of clearing them, buddy breathing, weighting without BC, using reserve J valves, calculating bottom times and all that are simply not taught so you will need to get with an experienced double hose diver to show you the ropes--and do a bunch of pool diving too. They breath different as well, with most single hose I was always told to breath normally, with a double hose I find taking long, slow, deliberate breaths to be more efficient and less tiring.
My winter project is to aquire an older scooter, I cannot wait to fly behind a scooter with a streamlined double hose and no BC.

Welcome to double hose dving.

James

[SeaRat]

Okay, a couple of points here. Even the older two-hose regulators allowed dives to considerable depths. James Dugan, in the book, Jacques-Yves Cousteau's WORLD WITHOUT SUN (a book about the first undersea colony, where divers were living underwater in 1963 for a month) states (and James, listen to the account of the "scooter-men"):

The scooter-men speed to Cage Five and the Black Masks oare able to continue their depth exploratin without going back up to their cabin for refills. Air expenditure at this stratum--165 feet--is six times that of the surface, and even our special four-bottle Aqua-Lungs containing air compressed to 3,000 pounds per square inch are quickly exhausted. As many as 40 four-tank Aqua-Lungs are used daily by the Oceanauts. Long ago it was determined that the absolute depth limit for a free diver on compressed air was 300 fet. We regard attempts to exceed that depth as foolhardy. However, in adopting a helium-charged atmosphere for the Deep Cabin, we were extending the old limit. Jean Alinat computed diving tables for the Black Masks and their helium halfway house and Captain Cousteau authorized them to go down as deep as 100 metres--330 feet. Using relays of fresh bottles brought down by helpers, the Black Masks cross the boundary and for a brief time touch 330 feet. They return unharmed to the Deep Cabin. (In fact, Kientzy confessed several weeks later that he had reached minus 363 feet, not as an attempt at a 'diving record' but because he just felt so well and so sure.)

These divers were using single-stage, double hose French LaSpiro Mistral regulators. They dove on heli-ox mixtures to 363 feet without discomfort.

I have dived the DA Aquamaster on a US Navy School for Underwater Swimmers to 120 feet in complete comfort, without any problems with the regulator.

The depth restriction is not so much on the regulator, as it is on the human physiology. It is not wise to dive beyond 120 feet withtout a lot of precautions. DIR folks regularly dive to the 200 to 300 foot level, and I don't think they take adequate precautions. The one thing missing is a recompression chamber on-site for these dives. They have whole philosophies built on the idea that they will prevent all decompression sickness problems with their techniques. History has proved them wrong on that account, and several best-selling books bare testimony to that fact (read Bernie Chowdhury's book, The Last Dive if you don't believe me). By the way, Frederic Dumas dove the Andria Doria just after it sank, with a two hose regulator and the Cousteau triple yellow tanks, and that was deeper than 200 feet in the 1960s.

The trick with a double hose regulator is to position the regulator correctly between the shoulder blades for best breathing. See this thread on this site for more about that:

vintagescuba.proboards2.com/index.cgi?board=instruction&action=display&n=1&thread=1142

You asked about "turning off the second stage" when it was free flowing. That actually is very simple. Simply pull the mouthpiece below the level of the regulator, and it will stop. The driving force is water pressure differential between the mouthpiece and the regulator (vertical measurement). The higher above regulator the mouthpiece is position, the more water pressure pushing against the diaphragm to continue the flow. Bringing the mouthpiece down under the level of the regulator effectively stops free flow. You don't have to turn anything off, just know how to use it.

Like James, I don't know about your question concerning the "yolk valves." All two hose regulators (with about three European older regulators and the new Aqualung Mistral as exceptions) used yolks to attach to the valve But if you are talking about the new valves used on doubles, with positions above the tanks instead of between the tanks, that will need a slight modification to be used by two hose regulators (but it has been done).

John

[broxton chuck]

Simply cut the hose that goes to the mouthpiece and it wont freeflow anymore. Now you D ring guys might argue the reg will still flow from the inhalation port, but if thats a problem stick your nose hole over it, and breathe normal.

[VintageDiverMN]

Chuck, you need to open a school for vintage SCUBA diving, there seems to be a real need to get these new kids trained the right way.

[SeaRat]

broxton said:

Simply cut the hose that goes to the mouthpiece and it wont freeflow anymore. Now you D ring guys might argue the reg will still flow from the inhalation port, but if thats a problem stick your nose hole over it, and breathe normal.

Actually, that is what Mike Nelson used to do, but with the exhalation hose. That way, the diver could continue breathing while making like he had no air. It was a good safety measure, and the public at that time was ignorant enough to buy it.

It wasn't until the movie Thunderball that James Bond got it right, and cut the right hose to force the enemy divers (who all conveniently used double hose regs, while the "friendlies" used single hose regs--all AMF Voit too) to the surface. If you watch that movie, you'll see those regs free flowing from the intake hose all the way to the surface. Some of my Air Force buddies made the Parascuba jump in that movie, from a HC-97 aircraft. They couldn't be paid (it was considered an Air Force training exercise for our quarterly requirements), but were given the AMF Voit twin tanks and regulator for their efforts.

John

[Broxton Carol]

There is a gentleman who I met, when he bought some banjos off me a few months back. He is an instructor, and is crafting a vintage gear dive course, and wants to teach it in the near future. All the good stuff like we learned as big bad teenagers when we hollowed out a stick and stuck it in the middle of our lips, and strolled about the bottom of the swimming pool at the swim club checking things out, while listening to "Im hurtin" by Roy Orbison! Gas was 25 cents, and a trip to the hospital was $3.50

[SeaRat]

Hi Chuck,

I've got a story about the ol' days. Some of my PJ buddies were off on TDY (temporary duty assignment) to Panama, I believe, for one of the Apollo space missions in 1969. They had to stay there a number of days, and got bored. I wrote about it in my diary at the time. I'm hoping to put together a book soon (it's been ten years now that I've been at it, so who knows). Anyway, here's an excerpt (I was stationed in Bermuda at the time):

From, Between Air and Water, the Memoir of a PJ
Copyright 2005, John C. Ratliff

17 Nov. 69--Diary Entry
If yesterday was dull, today was active. This morning, even with the poor weather, we made our scuba jump. This was my first in a year and a quarter. And I decided to try out the new Spanish fins I'd been issued. They worked pretty well, chasing after that damn boat.

This was a three-thousand foot jump too, also a first since school, practically three years ago. And it was a new 'chute, the S-17, which uses toggle lines (a line which closes off a vent in the right rear or left rear of the canopy), instead of sliding risers (which distort the canopy) for steering.

The jump itself went well, until I tried to catch the boat. I got out of the harness OK thanks to the foresight of taping the rear of the tanks to prevent the harness from catching on the regulator yolk. The tape forms a shield over the yolk and manifold. The boat wouldn't come to the upwind side of me and drift to me. It stayed down wind with its engines cut and made me out swim its drift. The waves were pretty good sized, eight to ten feet, and the winds were at 24 knots. We had a count of 27 from 3000 feet.

After the jumps (Schmidt and Mann jumped after me) the HC-130 dropped a MA-1 kit, three para-bundles and a free drop. Schmidt and I got in one of the 7-man rafts of the MA-1 kit, pulled in the line and bundles and then tied the two rafts together. I got sea sick again, just like on the Apollo Sim-Ex a week ago. I believe that its the engine exhaust we had to breath when the boat picked us up.

After the equipment was cleaned off we went to lunch and took the rest of the day off.

This evening I lifted weights again, after the touch football game. We lost the game in overtime on yards made in four plays.

'Got a letter from Mary Holt today and one from Miss Wolf and her class yesterday.

18 Nov. '69--Diary Entry

Not much happened today. I took an emergency procedures exam, fixed some of my paperwork, filled our jump tanks and in general messed around trying to get some tidbits done.

The crews from Panama are back as of tonight. Taylor and McComb, my next door "neighbors" (if there is such a thing in a barracks) came in on the birds. They didn't like Panama much. Too much rain.

November 19, 1969--Diary Entry

The Panama crew did have a ball acting a little rude at the hotel they staged at. As they explained it, there was this swimming pool at the Hotel El Continental, with the building itself right beside the pool and a bar on the bottom floor. While they were there on alert, they couldn't drink and had to look for other forms of amusements.

It all began with two waitresses setting poolside tables one night and a couple dozen ice cubes, dropped from the seventh floor (really the ninth story) of the building into the pool, resulting in some startled waitresses. Of course, when the waitresses went to investigate, they could find nothing, as ice cubes are next to invisible in water.

Then they began having fun in the pool itself. At night, mind you, two or three of them would get hold of the gutters and wait quietly for the pool to become ripple-less. Then they would hold up their heads so that just the top of their faces and their hands were showing. When the waitresses or other girls would come by, they'd say in a heavy Spanish accent "Psst, senorita, come here," and surprise the poor girls to no end.

Soon they were bored with even this, and when two lovely young ladies walked by, one of the fellows slithered out behind them, crawled like a snake following a chick, and repeated the above mentioned phrases. They told me that the girls actually screamed.

What I left out of the story is that they were almost invisible in the pool. It was night, and they were under the gutter. So these voices coming from the pool had no body associated with them...until, of course, one of the guys slithered out of the pool toward them (no names on this one).

Enjoy,

John

[treasureman]

when flying behind that scooter with a double hose, bring lots of aspirin, as those hoses are gonna beat your head like a tom tom. I dive in 4 knt currents and i get my head beat every time...ouch!

[nemrod]

"when flying behind that scooter with a double hose, bring lots of aspirin, as those hoses are gonna beat your head like a tom tom. I dive in 4 knt currents and i get my head beat every time...ouch! "

Nope it does not do that at all. Update, one of the two scooters I have bought works and has been dived both on a trip to lake Ouachita and also in a pool several times. The prop pitch is controllable and produces speeds from barely moving to about 3 mph I think. In any case at a good cruising speed of about 1.5/ 2 MPH give or take all is well. The hoses do pull back a bit but not much more than that. Now if you hold the scooter out in front so that the prop wash is beating you in the face it will just about blow your mask off so I imagine the hoses would vibrate as well--but---you are supposed to hold the scooter below you so that the prop stream is directed below you as well by keeping your elbows bent. Your arms can get tired so I have made a harness that clips to the "scooter" D-ring on the croth strap. This is all pretty much new to me.
James

[Yank Down Under]

John,

I have dived my Aqua Master to 200 feet without noticing any differences. That was just a bounce dive off of Kona sometime ago. My Heinke breathes better at all depths, but the Aqua Lung range will be much easier to get serviced. What ever you do, get the regulator serviced first. They rarely fail, but it's wisest to do so. If you get one from this site you will know it is safe.

I would suggest also, until you gain experience and confidence with vintage gear, that you search for the Sherwood twin tank manifold that allows you to use modern 3/4" neck tanks and two regulators. You can then run your 'new' vintage double hose regulator from the center and everything else from the second single hose regulator, that you already own. Nemrod also made a one piece, two regulator manifold, and that is what I used for sometime. Two 50 cu. ft. tanks are a manageable size for most applications.

Once you have the rig set up, spend some time in a pool and read some of the old instruction manuals. I learned to dive in 1959, by reading everything I could get my hands on. It's best to get instruction, but very few young instructors today know anything about vintage gear. Good Luck John.