Sidemount SPG hose and routing

[Wibble]

What's the recommendations for routing sidemount SPGs and HP hoses?

Need to do a fair amount of sidemount diving this year in preparation for a full cave course later in the year. Am doing some kit fettling -- the sidemount regulators are being serviced and even putting some tanks in test!

For stages and rebreather bailout cylinders (which I sidemount with bungees) I use a short 15cm/6" HP hose which is routed down the cylinder and folded back up and tied to the first stage with a piece of cave line. I find the thinner and more flexible Miflex HP hoses to work more reliably than the thicker 'rubber' HP hoses (have had several break over the years; normally starts with a 'pox' bubble and eventually leaking).

On sidemount I used the same Miflex HP hoses pointed down, but not tied back. To read the gauge I'd twist it into view. Not great and a faff to read.

Am thinking about using a couple of stiffer 'rubber' short HP hoses and routing them upwards. Concerned these will get in the way and be bent under my armpit. Alternatively would be to use Miflex HP hoses and let the gauge droop down; concerned this might be a nuisance with bungees and thick cold-water gloves.

Any other thoughts on routing?

Definitely not going to use AI -- buying yet another Perdix with AI + transmitters ~= $1,800!

(Only asking here as my drysuits are both in with the menders so having a dry period!)

 

[Guille G]

I use 6 inch hoses pointed backwards, as most in Mexico do. I push the tank down with my elbow when pulling the SPG up to check it, a bit annoying at first but I got used to it. Some use 9” hoses. I have tried it and it is much easier, though you have to make sure that you are tucking them back in between the tank and your side after checking to keep them tidy.

I’ve seen the Florida-style setup with stiff hoses pointing up, but never tried it so can’t comment on it.

 

[SlugLife]

I probably don't have "advice" (much less cave-training) but I can reflect having similar experience, going back-and-forth between 6-inch vs 9-inch, or tying the SPG hose to make the SPG point up. What I can say is a 6-inch hose, not tied, was a terrible experience trying to read the SPG. 9-inch was much better. I did tie the SPG hose, but also went to AI at almost exactly the same time.

 

[Wibble]

I probably don't have "advice" (much less cave-training) but I can reflect having similar experience, going back-and-forth between 6-inch vs 9-inch, or tying the SPG hose to make the SPG point up. What I can say is a 6-inch hose, not tied, was a terrible experience trying to read the SPG. 9-inch was much better. I did tie the SPG hose, but also went to AI at almost exactly the same time.

Floppy or stiff hoses?

 

[Robert H. Diver]

I use 6 inch hoses pointed backwards, as most in Mexico do. I push the tank down with my elbow when pulling the SPG up to check it, a bit annoying at first but I got used to it. Some use 9” hoses. I have tried it and it is much easier, though you have to make sure that you are tucking them back in between the tank and your side after checking to keep them tidy.

I’ve seen the Florida-style setup with stiff hoses pointing up, but never tried it so can’t comment on it.

Tried the lollipop method in my sidemount class, it was ok..I think I needed lighter spg’s because they were kinda floppy and not rigid even with thick rubber hoses. I switched to dual transmitters.

To the OP, buy used and save money you don’t need 2 perdix AI’s, just 2 transmitters (for now).

 

[drakcheslav]

I use 15cm rubber hoses, routed back, with light gauges with rubber bumpers (since they're not glass and brass).

I usually check them by either pushing the tank forward and checking the gauge by slightly angling it towards me, or, puling the tank by the valve in front of my armpit and checking it.

I found it works the best for me. I haven't tried 20cm ones, but some guys I know use them, and they're always floppy to be honest.

Here's how it looks.

 

[stretchthepenn]

I was trained with the "lollipop" method -- 2 x 9" (~23cm) rubber hoses angled upward toward the sternum.

Benefits:

• The SPGs will always be in a predictable location (often actually against your chest), meaning they're mostly out of the way and are easy to find.
• A 9" rubber hose is stiff enough when pressurized to stay in place and then return home when it's released, but it's also sufficiently long and pliable to pull forward easily for a glance.
• Both SPGs are centrally located; you can charge them with a light mounted on either hand, and while charging the faces, you won't send weird signals or accidentally dazzle your buddy.
• The pressurized/unpressurized status of your regulator systems is immediately obvious.

Drawbacks:

• The hose-and-SPGs are angled, so you'll probably need to angle your first stages on the posts. As a result, you might also need to tweak or entirely reconsider your LP port choices or hose-routing.
• The lollipops are always poking up, even on the surface.

This method worked fine, particularly as a beginner to SM with limited funds and a non-AI computer, but before long, I went AI and never looked back.

 

[Thrutch]

I just switched to transmitters, but I was using 9" Deep 6 rubber hoses routed back along the tanks with the light/thin SPGs. Never tried lollipopping, so I can't speak to that, but however you end up putting things together, I highly recommend the Deep 6 rubber HP hoses. The ferrules are really beefy, as is the hose itself, which helps keep them from being too floppy. Very well built. I've had other (admittedly economy) rubber and braided HP hoses start leaking from the ferrule after a few months of bending to check pressure, with one DGX hose even developing a big bubble that decided to reveal itself in the water right before my first AN/DP class dive (fortunately a classmate had a backup).

 

[SlugLife]

Floppy or stiff hoses?

• For a short time I had 6-inch steel-braided, and that was a pain.
• I currently have 9-inch flex (not tied, just pointing in-line with the tank) which works fairly well.
• I've also had a 6-inch rubber, tied with the SPG facing up on a pony-bottle regs (sidemount), and that worked well enough.
• I've since added AI, but left the 9-inch-flex with SPG, just because it's convenient for checking pressure on the surface, and doesn't get in my way.

I guess personally, I'd probably go with 9-inch. Generally preferring flex. However, if you tie the short-hose, then maybe rubber. I'd probably only do steel if you're certain you'll want to tie it.

I've never had an issue with flex-hoses, but some people think they're slightly less reliable. And with cave-diving, I know standards can be a lot stricter. I don't know if cave-diving types would consider flex-hoses as a "OMG failure point" versus "whatever, it's a hose."

Since these are bailout cylinders, another option might be to mini-SPG or button-SPG the tank. It's not convenient, but it (probably) doesn't have to be, because it's a bailout tank.

 

[Wibble]

Thanks for those pointers, really useful.

Most of my underwater activity is spent using a rebreather. It's only for this cave course that I'm going back to sidemount. Having said that, it's probably easier to fly with sidemount kit than the Revo, so all's not lost.

Think I'll try a couple of 6" stiff hoses -- need to replace a couple that have massive boils on the hose as they're leaking.

Hadn't thought about the slight angling of the regs which I also do with sidemount. Have a couple of Mk25's for the sidemount config where the "fifth port" has the short LP hose for BCD and drysuit. Will be interesting to try the lollipop method and see if that is more convenient.

Wasn't looking forwards to jumping in the local diving pond -- Wraysbury near Heathrow, London. The good thing is they allow solo open circuit, so I can fill my boots with laying line in there. Oftentimes the visibility is so bad in there it's like diving blindfold!