Drawbacks of Sidemount, compared to backmount diving

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Location
Subic Bay, Philippines
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Not a troll.... for those who are well familiar with the issues, please list and clarify your thoughts...

Please note; factual/researched points preferred over misconceptions and perceptions...

Cheers!
 
I would be interested in reading more on this subject, myself.
 
Limited choice in regulators that lend themselves to preferred routing of hoses. With back mount, anything goes, for SM you either; buy what works, make it work with mods or live with it. This means less potential for deals or using non-ideal equipment.
 
The only drawback IMO with sidemount is your wider. I dove manifolded 95's for 4 years . The weight dragging em in and out of the house, truck and fill tank seemed to invite injury eventually. The isolator is the achilles heel inwhich a leak there would deplete both tanks. Valves behind your head are OK, but under your arms is better. You may have to make 2 trips to and from the water without a cart but I carry the first one down on the initial site evaluation so Im walking down there anyway twice. I have 2 independent systems, each with 1st and 2nd stage, SPG and wing inflator. I dive a dual Nomad for redundant lift but only connect the one on the left tank and leave the right lp inflator tucked . No problem with routing on regs with a bit of experimenting you can get angles of hoses correct. I like long hose on left tank, behind my neck and in from the right side. Right reg on bungeed shorthose comes over right shoulder and has a hard 90 degree. SPG angle can be a challenge depending on where you want em to be. I clip mine in so they lay flat against my chest. VIP's are cheaper. No labor for tearing down and setting back up. Some may say having to change regs every few hundred PSI is a drawback to remain balanced but I dont find it to be a problem at all. On a rec dive boat I prefer an aluminum 80, but with a wide enough ladder, getting onboard with tanks attached is fairly easy and giant striding into the water does fine. Easy to feather a bad reg, easy to detect and shutdown a bad reg, bubble checking yourself is easy, the good far out weighs the bad.
 
I've dove both configurations. The only advantage backmounted, manifolded doubles provides in my expirience is that my backmounted collegues had an easier time getting on and off a boat. Thats it. In all other cases, in my expirience, side mount is the better option.
 
Totally speaking from ignorance, if sidemount is wider, how would that work on a liveaboard like Explorer Ventures or one of the Aggressor boats?

They're all set up with tank stations/bungees for one tank per person with barely enough room for a conventional single tank BC. I was on T/C Explorer a couple years ago and 6 of us shared a bench area. We took turns gearing up so we could all get past one another. Plus with a full boat (20) there didn't appear to be many extra tanks - or anywhere to safely store them.
 
For me the biggest point against is other people's lack of familiarity with it, especially in open water circles. So if I've got a new buddy it can mean a lot of talking stuff through before dives to educate them. Obviously that's a problem that diminishes over time.

Other things for a cold water diver (i.e. dry-suit) comparing against steel cylinders in back mount (e.g. twin 12 litre)


  • If I'm using the same heavy steel cylinders I'd use for back mount, then it can be more work to come out of flat trim. The config just wants to have weight low (cylinders), buoyancy high (wing). Running buoyancy through the dry suit helps with this as the buoyancy moves to stay high.
  • Your shape for going through holes is wider, but flatter. Not much wider, but a lot flatter. You just have to be aware. (1) (2)
  • You need a bit more lead on your belt if you're comparing against back mounted doubles with a steel backplate. No backplate = more lead.
  • If you're weighting yourself so you can hand off heavy cylinders that's even more weight. That said, you couldn't even consider handling off in back mount. Personally my cylinders stay on me. You're welcome to breathe off one, but they stay on me.

Aside from that, when compared to independent back mounted doubles, I can't think of any downsides.

(1) Some say you're no wider than your shoulders. That's possibly true, but my shoulders tend to disappear when I lift my arms above my head. The cylinders don't.
(2) ...and don't think about doing that fancy "swing the cylinders forward" thing to get narrow with steel tanks and a dry suit. All the weight goes forward and all the buoyancy is at the back. You end up a smidgen nose heavy. You need close to neutral cylinders for that as far as I can make out.
 
I've dove both configurations. The only advantage backmounted, manifolded doubles provides in my expirience is that my backmounted collegues had an easier time getting on and off a boat. Thats it. In all other cases, in my expirience, side mount is the better option.
Getting off a boat fast, at a hot dive site with current, requires gear that you can hit the water fast and be 20 feet down in the first few seconds. From what I have seen, on some of the most spectacular sites I have dove, the SM diver would be up on the surface like a duck paddling around, while the back mount divers would be on their way to the structure with all the life on it far below....when the SM divers finally get their gear set and descend, they are many hundreds of yards off the mark for the drop, and will be unlikely to experience much of hot sites like this..if any.

Beyond that, when I have seen sm divers at BHB, doing macro, they tend to drag their tanks on the bottom, stirring the silt as they go, whenever they try to get their face close enough to the bottom to see macro life...
I'm sorry, sure there are places the SM is desirable, but I think there is more that they are not desirable for.
 
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Not a troll.... for those who are well familiar with the issues, please list and clarify your thoughts...

Please note; factual/researched points preferred over misconceptions and perceptions...

Cheers!



Less streamlined causes more drag
People think this is preferable over backmounting for back related issues,but in reality the body mechanics to lower a tank is more stressful
For the open water boat operator,it is a nightmare having to deal with donning/doffing gear (yeah a Keys operator is about to ban it on his boat)
For the cave diver,it is actually causing more wear and tear on fissure type caves,where back mount is less stressful.
 
Getting off a boat fast, at a hot dive site with current, requires gear that you can hot the water fast and be 20 feet down in the first few seconds. From what I have seen, on some of the most spectacular sites I have dove, the SM diver would be up on the surface like a duck paddling around

Why are they paddling around?
In those conditions you clip your tanks on whilst aboard, jump in, descend. Any diver rigging kit in water with high currents is doing it wrong.

Beyond that, when I have seen sm divers at BHB, doing macro, they tend to drag their tanks on the bottom, stirring the silt as they go, whenever they try to get their face close enough to the bottom to see macro life...

If the tanks are beneath them its not sidemount (by definition). That's just a diver clipping tanks to D-rings with bad buoyancy.
 
https://www.shearwater.com/products/perdix-ai/

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