Single Tank Sidemount

[Glenn08]

My preference is twin 50's, valves down, with a Selpak manifold = two first stages, one on each valve. My 72 is too long to wear valve down comfortably. When I use the 72, I use a pony. I have wondered about two 72's sidemount, to position the valves in front of me, but I don't need that much air to match my buddy with his single 80. So my next ponder was sidemount with a 72 and a pony, or a 72 and a 50 (big pony). So I'm still pondering.

 

[victorzamora]

MScorpa, I've done single-tank sidemount (STSM) before and I didn't mind it. As long as you're diving an alu tank, the weight shift isn't bad. You end up hanging tank-side low for a bit at the beginning and then tank-side high at the end. I always use a frog kick, and there's a way of frog-kicking with your feet slightly out of alignment to allow for a twisting moment to be applied to compensate. I use that to compensate for my imbalance, and slowly migrate to the other side when the tank starts emptying. The guy I first started doing that with would carry a weight belt with unbalanced weight on it, and spin it during a few points through the dive. I put a 2# weight on the bottom of my AL80 for tank trim, and I do the same on my non-tank hip just to compensate for that weight....but I don't use lead to compensate for the tank's buoyancy.

Glenn, I've tried mismatched tanks (LDS was doing a pool dive, and I paid for two identical SM tanks. One was at 3000psi, the other was at 14.7 (completely empty). I had a steel 72 on one hip and a LP108 (I think) on the other. I was NOT a fan. I ended up unclipping both and putting the one with my longhose at the bottom of the pool so I could continue to help my buddy out (we were tweaking gear). I will tell you that anything other than a "standard" alu tank (neutral at half-full) is an absolute PAIN to dive offset with.

Having said that, I've pretty much given up on STSM. My fiancee, a buddy, and I did a two-tank boat dive a couple of weekends ago. We all had two AL80's for two dives. They used them as BM singles and carried one on each dive. I used mine as traditional two-tank SM and simply had the redundancy afforded by having both tanks. At the end of the day, the dive op didn't know any different. Well, I told them....but, like, it was the same as far as they were concerned. I dove off of a boat, and didn't need any DM help either way....just a good buddy. I see no need for STSM, except for in rare scenarios. eg: Most diving in Roatan is one tank off of a boat, and you switch tanks between dives as you come back to shore. In that scenario, I'd be very tempted to just SM the one tank.

 

[TheRedDiver]

The owner of island scuba in puerto rico (pedro) does stsm and a sms50... he uses a 2# ankle weight on the opposite side at the beginning of the dive, moves it to center at 1/2 tank, and to the tank side as it gets low... might have 2 mid points, didn't pay attention too much, but when I asked how he compensated for the tank, he said he moved it across the belt to compensate throughout. He is a photographer and managed to have really good stability, etc... in fact it looked so comfortable I started looking into sm config.

 

[MScorpa]

I guess I forgot to mention I was probably only going to have time to do a single dive in the evening when/if we get done with work early for the day. That was the benefit for me to use a single tank instead of paying for two tanks and using only half the gas. I am also packing as little recreational gear as possible since I will need to bring a lot of equipment for work. I don't get any real benefit from side mounting the tank over back mount except that is how I have all my equipment set up and how I've been diving for a couple years now so why not?

I definitely understand the benefit of diving two tanks with regards to redundancy and ease of trim. But, I will probably be going only like 30-40' deep in open water. I'm not too worried about redundancy. I dove STSM with an al80 in the quarry over the weekend and didn't have any trouble with trim. It wasn't too hard to compensate for the changing buoyancy of the tank (it's -2lbs full and +4lbs empty) and I didn't feel like I was struggling to prevent rolling at all. My tank was set up on the left side and I shifted one weight slightly to the left so the tank change seemed more like +/-3lbs.

I did originally set up my regs breathing the standard short hose and mounting a 40" spare to the tank with bungees and a breakaway clip but Andy has guilted me into wanting to mount a long hose now lol.

 

[DaleC]

There's some footage of me singletanking using my old sandwich plate here:
[video=youtube;19Ax6Wim4FA]http://www.youtube.com/watch?v=19Ax6Wim4FA[/video]


And some using a single 40 and simple harness here:
[video=youtube;INFnmBUzbh0]http://www.youtube.com/watch?v=INFnmBUzbh0[/video]

And some using a DIY wing here (not much sm footage though):
[video=youtube;F_JeHryhrgU]http://www.youtube.com/watch?v=F_JeHryhrgU[/video]

 

[Kevrumbo]

A Fun SUP/Scuba Dive Off Buoy B & A, La Jolla Shores, San Diego - Unified Team Diving

 

[tiki_bill]

A Fun SUP/Scuba Dive Off Buoy B & A, La Jolla Shores, San Diego - Unified Team Diving

What rig is this? At 3:27 it looks like the wing is gonna float off his back. You could practically scooter between the gap.

 

[DevonDiver]

Waaaa?!?!? Waaaaa?!?!? What is THAT???

 

[DaleC]

Really? It's just a wing. Someone sidemounted without spending $500-1000 for a purpose specific rig - call the etiquette police.

 

[MScorpa]

What rig is this? At 3:27 it looks like the wing is gonna float off his back. You could practically scooter between the gap.

Waaaa?!?!? Waaaaa?!?!? What is THAT???

View attachment 165443

LMAO you guys crack me up! This rig must be a work in progress...

Really? It's just a wing. Someone sidemounted without spending $500-1000 for a purpose specific rig - call the etiquette police.

That is pretty bad, not what I would have expected from one of those fancy UTD divers. I thought spending obsurd money was a prerequisite for UTD?

Anyway, this is pretty much the exact type of dive I want to do, slipping through the weeds (like the streamlined guy).