Why use a double hose

[EFX]

I was going to ask if DH was harder to breathe than SH. Someone compared their Kraken to a SH reg and said it was the same or very similar. So my question is: how easy is it to breathe compared to a CCR? I've read that it takes a little more effort to exhale a CCR than a SH OC system.

 

[Nemrod]

DH regulators generally have very low exhaust effort. A DH like the Kraken or any Aqua Master modified with the HPR valve will likely have a lower cracking point/effort than a SH regulator. A DH regulator will have a very strong Venturi favoring divers who learned to take long, slow inhalations after the Venturi assist is establsihed. I refer you to the diagram I posted earlier in the thread.

The new DH diver who insists on using his double tank bent tech plate with a single tank perched high atop the center ridge and then worse with the valve hiked up behind the head will be a very unhappy little DH SCUBA diver. The main diaphragm MUST be located right up against the back and centered between the shoulder blades or lower.

I have no idea regarding a suicide machine, oh, I mean a CCR.

N

 

[Topcat414]

I dive a DA upgraded with a Phoenix and an HPR. Once you learn that you don’t have to pull a breath out of it to make it cycle like a single hose, you will find it breathes easier and more naturally than a single hose. In reality you are breathing the hose volume and the reg keeps the hose filled. That’s why a long slow breathing is beneficial.

I am one of those guys that does have a bp/ wing but I push the tank as low as it can go. I have no issues with the reg mid neck height. My air consumption was immediately improved once I started breathing the DH correctly.


Bryan just announced he is closing for a while because of his day job demands. But Jerrie at diverdowndhr.com has been connected with Bryan for a long time and can do service as well as help you with a full Phoenix/hpr system if you want one.

 

[dead dog]

I think older cars are easier to repair yourself.

Yeah, like old Ford Flatheads, after you tear it down and rebuild it and have parts leftover and it still runs. lol

 

[AfterDark]

For the most part, the horizontal position was fine. However, you are correct about placing the body in a different position will affect the regs breathing resistance. On one reg, it breathed much easier when I rotated to left or right side. It was also important to place the first stage between the shoulder blades; too low or too high affected the breathing resistance. Nonetheless, it was fun, even if the reg had a higher breathing resistance.

The solution to this is a crotch strap adjusted correctly. The reg needs to be between your shoulder blades regardless of the divers position a properly adjusted crotch strap will keep the tank in place.

 

[tbone1004]

I was going to ask if DH was harder to breathe than SH. Someone compared their Kraken to a SH reg and said it was the same or very similar. So my question is: how easy is it to breathe compared to a CCR? I've read that it takes a little more effort to exhale a CCR than a SH OC system.

The breathing profile is more similar to a rebreather than single tanks with how you need to breathe like @Nemrod said. Total WoB is hard to quantify against CCR's as a whole though. A chest mount rebreather like the new O2ptima will have a negative WoB for the inhale side, but a fairly good bit of resistance on the exhale. A backmounted counterlung rebreather like the JJ will have a negative exhale WoB, but a bit more inhale resistance. OTS lungs are more balanced, so it's hard to quantify.
Traditional single hose regulators have a very low inhale WoB, but a higher exhale WoB because the exhaust diaphragm is a few inches below your mouth. The double hose feels very different than a single hose regulator because of this and will feel more similar to a backmounted counterlung rebreather

 

[PfcAJ]

To me, a double hose breathes like a snorkel.

 

[EberWolf]

I got my Kraken in late Dec last year. I was finally able to get it in the water last week. This was one of the many upcoming shakedown dives with it. I'm using a stainless freedom plate and a VDH 35# wing. I used a standard 2" HOG Harness. From my dives last week I learned I'm more compressible at depth than I thought I was. Cinching down the waist strap is easy. Definitely recommend an easily adjustable crotch strap. I'm in the process on making one for mine. So far I love how it breathes. Little tweaks here and there but that's expected with any new gear.

 

[Perryed]

One other advantage is price. You can get into a good double hose for a couple hundred dollars. You can accessorize like a car and go up from there, but a good operating vintage double hose (if you overhaul it yourself) will set you back around that. And has been said, you can service it with help from the internet and the great folks here!

 

[lexvil]

A double hose doesn’t breath better than a single hose, it breaths differently. If you have a single hose that doesn’t breath easier, in general something is wrong with your single hose reg.
Once you get used to the DH and how it breaths you can dive without thinking about it, where you will feel a big difference is when you don’t dive one all the time, it takes a different set up of equipment the get the best performance from a DH, a SH can be used with the same set up regarding tank placement but is far more forgiving as far as placement goes.
Never expect a DH to perform well until you get everything set up properly as mention/demonstrated earlier.

The advantages to DH other than moving exhaust bubbles to the rear are few but that one thing can make a big difference in photography/video you may not notice the sound difference until you do a video, it’s remarkable how much quieter it is, fish notice it as well.

I started diving in 1971 with a voit DH and used it for many years, I recently sold my second Kraken, I really don’t miss it except for the cool factor I guess. I do have a 1959 frosty can with a cyclone and an HPR, thought about buying another Phoenix to put on it but deep down I know I will never dive it, probably need to sell it.