Sidemount - why only one long hose?

[TheCatFish]

I've got a 5' and a 7'.

I had a short hose and a 7' because that's how I was instructed. A technique that seems to be carried over from backmount doubles.
When one of the hoses eventually rots out I'll replace them both with equally sized hoses. Haven't decided if they'll both be 5' or 7'. Probably will come down to whichever is easiest to access. Inititally my short hose was around 3' long but I decided to get a second long hose. The area I was in didn't have another 7' readily available so I bought the 5' (might be 6'?) and called it a day.

I tuck the hoses into the tank bands and then pull out just enough so that the hoses each go behind my neck and clip onto d rings at my clavicle.

 

[halocline]

The long hose is typically wrapped around your neck, not tucked into tank bands. You're welcome to use whatever configuration works for you, but a short hose on the right tank clipped to the right D ring works best for me.

The long hose has two loops, both of which are initially stowed under tank bands. When you don the right tank, you pull one of the loops out and that gets routed around the back of the head. The other one stays in the tank bands, unless you’re air sharing and then you pull that loop out.

I’m always a little surprised at some of the responses on this forum; it’s interesting how differently people configure side mount. It’s like the Wild West, lol. I can’t possibly imagine what the advantage of two long hoses would be, unless you plan on sharing air with two people simultaneously while holding your breath. For cave diving, which is how I use side mount, I need a 7 ft hose to share air single file in restrictions, but the other tank is definitely for me, nobody else. Hence the short hose/bungee necklace.

I also never breathe 500PSI from one tank before switching, for me it’s 200 PSI (5-10 minutes depending on depth) and then switch. I want the tanks as balanced as possible. Assuming starting with 3K PSI in each tank, it goes 200-right tank, then 200 left tank, then 200 right, and so on. The left tank doesn’t ever get lower than the right. That’s because it’s my emergency air and BC inflation.

If you’re diving SM in a cave, I don’t think you want to deviate too much from that approach, but in different environments, whatever works!

 

[TheCatFish]

The long hose has two loops, both of which are initially stowed under tank bands. When you don the right tank, you pull one of the loops out and that gets routed around the back of the head. The other one stays in the tank bands, unless you’re air sharing and then you pull that loop out.

I’m always a little surprised at some of the responses on this forum; it’s interesting how differently people configure side mount. It’s like the Wild West, lol. I can’t possibly imagine what the advantage of two long hoses would be, unless you plan on sharing air with two people simultaneously while holding your breath. For cave diving, which is how I use side mount, I need a 7 ft hose to share air single file in restrictions, but the other tank is definitely for me, nobody else. Hence the short hose/bungee necklace.

I also never breathe 500PSI from one tank before switching, for me it’s 200 PSI (5-10 minutes depending on depth) and then switch. I want the tanks as balanced as possible. Assuming starting with 3K PSI in each tank, it goes 200-right tank, then 200 left tank, then 200 right, and so on. The left tank doesn’t ever get lower than the right. That’s because it’s my emergency air and BC inflation.

If you’re diving SM in a cave, I don’t think you want to deviate too much from that approach, but in different environments, whatever works!

I just prefer the symmetry. And the fact that I can donate either regulator or tank conveniently without making any other logistical choices. I also swap every 300psi rather than every 500, but YMMV. There's time's I've gotten too focused on something and drained my tank down by 500psi before swapping. Which is another good reason to practice earlier swaps too.

 

[Bowers]

I have tried lots of hose options and had no issues with 2x 7' hoses. I did move back to a short on left because it packs in the bag nicer. My wife uses 2 shorter hoses but I keep a 7' on my right because I dive mixed teams a lot with steel tanks.

Just another option to think about, if you are diving aluminum tanks then it is completely feasible to unhook the right tank and hand it to the buddy. The buddy then can clip the tank like a stage or swap their empty tank to you and both of you can exit with full mobility and freedom. In this case a long hose has no benefit and 2 shorter hoses are great options.