Question Rec cold water diver: Single, Double or Sidemount? (focus on safety)

[SlugLife]

First, my 2x 19cu bottles and regs:

I prefer the paracord version, even though it was intended to be a quick-cheap-and-dirty.

Tanks and rigging. Blue tape covering my contact-info (in case bottles are misplaced)

Rigging Bottom

Bungies

Rigging top

Regulator 1: Scuba Pro MK10, G250, button-SPG.
Short-BCD hose could be removed, I forgot I had it on there. Same with the necklace.

Similar setup, but yoke, and normal SPG. (Humidity got inside the SPG, but it works. Just a random one from my used collection)

Breakaway clip #1: A zip-tie and o-ring.

Another breakaway clip. I hacked off the crappy plastic clip off and added a bolt-snap.

SOLAS tape!

 

[SlugLife]

My 6cu bottles aren't rigged up as nicely. I mostly keep the around as loaners or travel or messing around on a beach for a couple minutes (13cu would be better for travel, but I got these dirt cheap). I'll often swap out the 2nd stage with a G250 (only takes a few seconds) whenever I use them.

A quick note on sizes:

• 19cu is my preferred recreational size. Should handle most common emergencies up to 130ft. (note: I'm skipping 20 pages of debate, calculations, etc. This is a rough recommendation) The 19 is honestly no worse than the 6cu when in the water in terms of being in your way.
• 13cu is often an ideal travel-size. Smaller than the 19, but ~66% the size, but you should maybe skip the safety stop, and maybe stick to 100ft or less.
• 6cu is my "minimum recommended." It'll be adequate for saving your life in many scenarios. No need to panic, but you'll want to immediately head for the surface, skip safety stop. Perhaps also try to stick to 60ft or less. Based in my testing, I use about 100psi per breath at 8ft deep, so they don't last that long.
• 3cu and 1.7cu or "Spare Air." I mean, I won't stop you from buying the ones I have listed.
• 30cu and 40cu - 1.5x or 2x the air of the 19cu. However, I know several divers who own this size, call them "pony bottles" but literally never bring them on dives. The 6/13/19cu you have on your person is 100% better than the 40cu you left at home. I don't know if they're actually annoying to carry or deal with from personal experience, but some people here on SB don't seem to mind them.

Hose is routed in a "W" shape, under the bungie.

 

[Wildsparrow]

Wow, thank you so much for all the pictures and descriptions I probably need to read that 2 or 3 times to get everything correctly So many nice details

 

[drakcheslav]

I've met a couple of divers from lake garda, and their preferred way of diving with a single tankt and two posts at minimum. Due to the free flow.

I used to dive a 15l two post tank, and instead of going to a 2x12 for a technical advancement, I went to sidemount due to my back problems. So I recommend if you have limited mobility and back/neck problems sidemount. You'll learn how to dive in both rough waters and on boats, and on long treks.

If you don't have back problems doubles are set and forget setup.

 

[BlueTrin]

The other thing for doubles is that if you go for a manifolded twinset, you need to be at least able to reach the manifold to isolate the tanks.

If you can’t, some people invert their twinset and put a halo, or use a remote lead (a slob knob, Custom Divers Twin Set Manifold Remote Lead), but then you may consider then sidemount?

 

[SlugLife]

Wow, thank you so much for all the pictures and descriptions I probably need to read that 2 or 3 times to get everything correctly So many nice details

Questions welcome. I skipped over a lot of details that might normally go in a "tutorial."

Most of the setup is SideMount-inspired, but works just fine for slinging. You can also get pre-made pony-bottle rigging. Just make sure the hose-clap is an appropriate size for the diameter of whatever bottle you get.

Tank Strap Kits - Hose Retainers

Cylinder Stage/Deco/Sidemount Straps and Hose Retainers

www.divegearexpress.com

 

[Marie13]

Questions welcome. I skipped over a lot of details that might normally go in a "tutorial."

Most of the setup is SideMount-inspired, but works just fine for slinging. You can also get pre-made pony-bottle rigging. Just make sure the hose-clap is an appropriate size for the diameter of whatever bottle you get.

Tank Strap Kits - Hose Retainers

Cylinder Stage/Deco/Sidemount Straps and Hose Retainers

www.divegearexpress.com

Geez, is hose clap a pony disease?

 

[rx7diver]

The other thing for doubles is that if you go for a manifolded twinset, you need to be at least able to reach the manifold to isolate the tanks.

If you can’t, some people invert their twinset and put a halo, or use a remote lead ...

... or wear independent (i.e., non-manifolded) doubles. I considered, briefly, wearing my LP50's as independent doubles. Ultimately decided against (since the cylinder capacities are so small).

I think, though, that old-school 72's worn as independent doubles would be quite nice--though you would lose the small size (6.9" OD vs. 5.5") and light weight (27# empty weight, vs. 19#) of LP50's.

rx7diver

 

[BlueTrin]

... or wear independent (i.e., non-manifolded) doubles. I considered, briefly, wearing my LP50's as independent doubles. Ultimately decided against (since the cylinder capacities are so small).

I think, though, that old-school 72's worn as independent doubles would be quite nice--though you would lose the small size (svelt?) and light weight of LP50's.

rx7diver

Yea I was scared of mentioning independent here, some people have strong opinions

last time I paired with two randos at my local lake, one of them keep criticising the other for using independent doubles, I was mortified.

Agree with you : independent doubles are a better choice if you cannot reach the manifold.

 

[L13]

SM not ideal for boats, depends on local customs if it is allowed or not.

SM is just fine for boats, but I have heard that some boats don't allow it.

Personally I've never experienced that. This last summer I was diving in the great lakes from a boat using SM, no problems and no questions asked. In september I dove SM for a week in Cozumel, again no problems. In both cases I did call ahead to make sure it was ok.