Hose Length and Double Hose Positioning

[SeaRat]

Years ago I came to the conclusion that hose length for a double hose regulator was critical in positioning the regulator correctly between the shoulder blades. So I started experiments with different hose lengths, using SCBA hoses instead of regular double hoses (Voit or U.S. Divers Company) hoses. I put them onto either the Hope-Page mouthpiece, wy Overpressure Breathing mouthpiece, or a La Spiro Professional Mouthpiece. Here's a few photos of my experiments over the years.

IMG_1423 by John Ratliff, on Flickr
This shows extremely long hoses on my Healthways Delux regulator. It helped this regulator, which doesn't have a Venturi. Note also that this set's harness has no waist strap, allowing me to either use the crotch strap with a La Spro weight belt buckle, or my onw four-point harness attachment to my hip connectors on my Para-Sea BCD.

IMG_1256 by John Ratliff, on Flickr

IMG_1254 by John Ratliff, on Flickr
With longer hoses, I could drop the regulator below the handle of the backpack.

IMG_0013 by John Ratliff, on Flickr
My Trieste II regulator is equipped with "super-stretch" hoses, again allowing a lower position on the back.

IMG_2647 by John Ratliff, on Flickr
Here, I'm diving my Sportsways Hydro-Twin, with normal length grey Voit hoses and a Voit mouthpiece. But when I stand with this configuration, the mouthpiece almost strandles me.

Now, I know the some diver will talk about hose length and ease of breathing, that the longer the hose, the worse the breathing characteristics. But I'm not seeing this in practice, and the longer hoses are much more comfortable as well as lowering the regulator on my back.

John

[h2operations]

Which SCBA brand did you pull the hoses from ?

[vance]

There are a number of gas mask hoses available on eBay. They are 1" x 1"-ish. I haven't found any with cuffs on one end to use with larger than 1" mouthpieces.

They work pretty well, but the regulator horn ends tend to be loose. A rubber sleeve slipped over the horn (like the excess from a duckbill, or a 3D printed sleeve) will take up the slack.

I buy canvas covered Russian 1" hoses now and then, and strip off the canvas. They work well for Scubas, etc.

[SeaRat]

Oct 28, 2022 12:35:20 GMT -8 h2operations said:

Which SCBA brand did you pull the hoses from ?

I think I got both Scott and MSA hoses, but realize that this was 20-30 years ago when the SCBAs still had corrugated hoses. I think they may be rare now.

John

[h2operations]

Thanks. I thought about using them as I have access to them pretty readily just never tried. I wondered if the length would affect the air draw to any extent that would be noticed.

[SeaRat]

Oct 31, 2022 16:24:46 GMT -8 h2operations said:

Thanks. I thought about using them as I have access to them pretty readily just never tried. I wondered if the length would affect the air draw to any extent that would be noticed.

I think it depends upon the regulator. I have used longer hoses on my U.S. Divers Company Overpressure Breathing regulator without any noticable effect.

IMG_1235 by John Ratliff, on Flickr
Me, with my USD Overpressure Breathing regulator, predecessor to the Mistral.

John with PJ tanks on Lamprey Video by John Ratliff, on Flickr
Here I'm using high stretch hoses on my Healthways hybrid Scuba regulator (Gold Label Scuba mechanism inside the original Scuba boxes). This regulator has a very advanced Venturi tube.

IMG_1167 by John Ratliff, on Flickr
Here I have the longer hoses into a La Spiro Professional Mouthpiece (no non-return valves) on my Mossback Mk3, an Aquamaster with a modern first stage.

John

[SeaRat]

I just found these photos taken of me by Sid Macken, former Historical Diving Society President, in Big Cliff Reservoir ten years ago, September 1, 2012. They show how the longer hoses on my Mossback Mk3 regulator work so well to allow lower positioning as well as greater freedom of motion of my head.

DSC00294 by John Ratliff, on Flickr

DSC00286 by John Ratliff, on Flickr

John

[Aquala1]

For longer hoses I use the hoses that came on my Argonaut Kraken. I recently picked up this Aquamaster (without hoses) and according to the serial number it was made in ‘61. 1961 was the first and only year that USD used the super-stretch hoses and the Kraken hoses are the closest I know of to originals. As a side note, 1961 was also the first year of the curved mouth-piece.





Compared to a standard DA hose-set, they’re considerably longer.

[Aquala1]

I just realized that “The Scuba Museum” has the super-stretch hoses that came on the Kraken available for sale.

www.thescubamuseum.com/Online%20Store/onlinestore.htm#!/Super-stretch-black-EPDM-hoses-1-5-to-1-inch-cuffs/p/485838313/category=20189276

[SeaRat]

I thought everyone would enjoy seeing where J.Y. Cousteau had his regulator in the earlier days of diving.

IMG_0205 by John Ratliff, on Flickr

I got this off Facebook, and don't know who took the photo.

Note also the Squale oval mask.

John

[SeaRat]

Here's another look ah hose length in the early days. This is a Cousteau/French Navy photo, used in a CocaCola commercial.

IMG_0219 by John Ratliff, on Flickr

If you look closely at the diver drinking the CocaCola, you can see a La Spiro regulator mounted on a side-mount J-valve.

John