Weight between double and singles on and off the boat

[rx7diver]

For me, when recreational scuba diving, the closest I feel to skin-diving (snorkeling) is when I am using a single cylinder that doesn't have a huge capacity. This is one of the reasons why I prefer to use a Y-valve (two complete regs) on a single cylinder when (solo) recreational diving in the 60 ffw range. This configuration offers protection against the loss of a single regulator. And the moderate capacity of the cylinder means that my BC never has to be inflated very much when I'm wearing a thin to medium-thick wetsuit. There is less drag, and there is less inertia compared to back-mounted doubles. And 60 fsw is not so deep that the (extremely improbable) loss of air from both regs is not an easily survivable event.

This (i.e., Y-valve on a single cylinder) is such an easy, enjoyable, relatively lightweight configuration (for me)!

For (solo) recreational dives deeper than ~60 ffw, I want more redundancy, so I use my baby doubles (isolation-manifolded Faber LP 50's), which, though a delight to use for these dives, leave me a bit farther away from that singular, exquisite feeling of skin-diving.

FWIW,
rx7diver

 

[grantmac]

Sidemount for me is easier everywhere. Easier to move tanks around on dry land. Easier on a boat. Easier to rent tanks.
I hate lugging my twin 12l around, my single 12l can be carried one in each hand easier.
The only time I'd prefer backmount is if I need more than 4 tanks.

I'll say this: you have to actually learn how to adjust and dive the system in sidemount. It seems a lot of people try to sidemount with the backmount attitude of throwing it on and going diving.

I dove a off a small hard boat yesterday with giant stride entry and ladder exit. I was the first person in the water and the only diver in doubles who didn't need help up the side or kitting up in some way. Off a rhib I'd have had even more advantage (I dive doubles off rhibs for work and it's a mess).

In my opinion the best time to learn sidemount is before you get stuck with the backmount mindset.

 

[Wibble]

Those who sidemount just get on and do it.

It is more of a faff and needs plenty of practice to smoothly kit up, especially on a boat. Nearly every time I’ve seen a sidemount diver on a boat they look smooth and competent, in fact they’re hardly noticeable at all. Same with the sidemount divers in overhead environments or anywhere else.

The great benefit of sidemount is the complete control of the kit. Splitting the weight for a long or arduous carry, be that over shingle to the water’s edge or climbing ladders underground — using a rucksack to hold the cylinder or smaller cylinders.

In the water you’ve full access to the valves and all hoses with full leverage on the valves (have found backmount knob twiddling to be extremely sub-optimal in this respect, once needing another diver to free a jammed valve). A sudden and unexpected freeflow is massively disorientating but trivial to deal with on sidemount.

There’s kitting up tips that the cavers can teach. I mean the cavers who dive and who use pragmatic kit configurations. For example use standard stage rigging kits with big boltsnaps so you just clip the stages on like deco/bailout stages, then deal with the bungees in the water to push the cylinders back.

It really helps if you’ve a pragmatic instructor rather than one that teaches a single configuration. Sidemount is all about subtle tweaks and adjustments to get the kit to work for you. Having someone with an eye to suggest those adjustments saves a lot of time.