La Spiro Professional Mouthpiece

[SeaRat]

I was reading through the Science Diving International, from 1973 book's article, An Attempt to Live Objective and Subjective Performance of Sport Divers' Regulators" by R.J. Nyman and J.G. Van Der Walt, when I happened upon an interesting graph, Figuer 17 (see below):

Non-return valves 001 by John Ratliff, on Flickr

The graph showed the effect of fitting non-return valves in the mouthpiece of a twin hose regulator, a La Spiro Mistral. It showed the same configuration of hoses, first fitted with the Aquastop mouthpiece and second fitted with the Professional Mouthpiece. Then I got to thinking, I have a Professional Mouthpiece, and it's fitted on my DA Aqualung (Broxton) regulator:

DA Aqualung-2 by John Ratliff, on Flickr Note in the background the Hope-Page Mouthpiece, which was then on my Mossback Mk 3 regulator (along with my Suunto dive computer).

Aqualung Regulator-1 by John Ratliff, on Flickr

I have my Mossback Mk 3 fitted with my Hope-Page mouthpiece:

John & Mossback Mk 3-1 by John Ratliff, on Flickr

What would happen if I put this Professional Mouthpiece on my Mossback Mk 3? The Mossback Mk 3 is one of my best-performing regulators, so what would it be like? Well, I did and I dove it yesterday, using my twin steel 52s for the first time in over a year. The results--wow! That does make a difference.

IMG_1167 by John Ratliff, on Flickr

I dove it for over an hour, testing it in various positions. I flooded it and then cleared it by initiating a free flow and exhaling while turning on my left side without problems. A little later I again took it out of my mouth, and switched to my Calypso second stage, then switched back and cleared it manually by blowing into it with my head turned slightly to the right (putting it left-side down), then rolling onto my back while exhaling without problems. The breathing stayed the same, almost effortless. I liked it better than my old USD mouthpiece that I had on it earlier this year, and the mouthpiece on the Hope-Page was pretty good, but the effort slightly worse due to the non-return valves (silicone, but older) in the Hope-Page mouthpiece. The Hope-Page is now on my DA Aqualung (Broxton) and the Professional Mouthpiece is on my Mossback Mk 3.

I did another experiment, actually I was observing the very tiny minnows up-close with my SeawiscopeEY, and found that they were not affected at all by breathing noises. Usually, I have some response, even with the double hose mouthpieces, but this time--no response. I think that the mouthpiece being solid brass may have further dampened the breathing sound for these small criters. I saw several species of minnows, one of which was a black-colored, full-bodied minnow about as big as my thumbnail, and they did not respond at all to my breathing. I had my eyes about three inches away from these small fish in shallow water too.

I went home, and opened my Mossback Mk 3, and to my surprise there was no water in the can itself. Because these hoses are longer, super-stretch hoses, the water never got past the uphill part of the loop so as to enter the box.

All in all, a very promising experiment--the Professional Mouthpiece is staying on my Mossback Mk 3 regulator.

I have a DSV mouthpiece from VDH on my Trieste II, and it needs it as the Venturi is such that the Professional Mouthpiece would allow blow-by.

John

[snark3]

John that's a nice looking rig you have there. I find it amazing how much we tinker with our gear to get it just the way we want it. I'm always trying to improve something in my rigs, maybe the way a hose is routed, maybe where we put our weights.

[technidiver]

I'm surprised nobody has made a run of metal mouthpieces similar to the La Spiro Professional or even just the standard spiro mouthpiece. Looks great, works great.

John, is it a 1 inch hose loop that fits with the mouthpiece?

TD

[SeaRat]

Jul 14, 2019 13:57:25 GMT -8 technidiver said:

I'm surprised nobody has made a run of metal mouthpieces similar to the La Spiro Professional or even just the standard spiro mouthpiece. Looks great, works great.

John, is it a 1 inch hose loop that fits with the mouthpiece?

TD

TD,

Yes, it is a one-inch hose loop that fits, as maybe you can discern from the photos above.

By tha way, anyone who wants a copy of the paper that has this graph in it, let me know via PM, and I'll e-mail it to you. My book has come somewhat apart, and this paper is now sitting on my desk, awaiting scanning.

John

[SeaRat]

I used my Professional Mouthpiece on my Mossback Mk3 regulator again this afternoon, diving for about an hour. I had a leaky duckbill, and so had to clear the exhalation hose several times, but the mouthpiece worked very, very well. (I'll get a new duckbill soon.) I was able to get within inches of small, skittish fish on the bottom, and even came upon a steelhead in the water which didn't even bother to change directions as I swam within two feet of it. I'm really wondering whether the metal mouthpiece dampens the sound of breathing. At one point early in the dive, I had an eighteen inch smallmouth bass looking directly at me, studying me unconcerned. I went to take a photo of it, powered up my Canon PowerShot SD500, and got this message on the screen, "No Card." Oops, forgot something in the hurry to get going. So, I made this an observation dive. Saw a crawdad, got down close and observed from a few inches away, and watched as the second row of legs was constantly scouring over the bottom for something edible, and if it found something, without looking brought it up to its mouth. It was a great dive today.

John

[vance]

Nice! I'd like to take a shot at making a good mouthpiece sometime. I've stood in the plumbing aisle of a hardware store pondering pieces that could probably make excellent mps with some intelligent mods!

[vance]

The Russian AVM-1/AVM-3M metal mouthpieces are a good starting point for a custom setup. I have one I put modded Sportsways wagonwheels in. It seems to be pretty good.