Wreck Diving on Sidemount or Backmount Doubles

[MichaelMc]

I think arm strength matters for sidemount for on land rigging.

You can get away with more lack of strength in backmount, just slip your arms in and standup. There is no issue of kitting or de-kitting while holding a tank up.

The pandemic put me in better physical share and a recent SM dive was much simpler in terms of rigging hassles as a result.

 

[rjack321]

Backmounted doubles for all the reasons @grantctobin described. You can always decide to sidemount later (for fun or because you actually need it). Its vastly preferable to be able to pick and choose kit based on your needs and mood than being locked into any one thing (although budget can be a factor especially for rebreathers). Backmounted doubles are much easier to get proficient with than SM so add that skill set next.

 

[stuartv]

I prefer BM doubles for anything other than a situation where SM is actually needed (which - as I have not done cave training yet - has never happened to me).

However many cylinders you can carry in SM, you can carry that many plus 2 more on your back, in BM.

As was noted upthread, if you lose a 1st stage, you can still breathe all your gas in BM. Though, to be fair, that's not the WHOLE picture. If you lost a 1st stage in SM, you COULD (possibly) breathe one tank down and then move the working 1st from one cylinder to the other. Or move a deco reg to the bottom gas cylinder. Whatever. There are options that COULD allow you to still use the gas in the cylinder that lost its 1st stage.

If you're on a boat where using a gear line isn't feasible, BM is way easier to walk around in when fully kitted up. E.g. when getting from your seat to the boat exit.

I was diving with a couple of pretty experienced technical sidemounters over the last few weeks. One of them told me "I love SM. But, if I need to carry more than 2 deco cylinders, I'm going BM." And that seems VERY reasonable, to me. Just having learned how to dive with 3 deco cylinders, I feel like that would have been ridiculously harder if I had my 2 main (bottom gas) cylinders also slung at my sides instead of on my back.

 

[RainPilot]

One of them told me "I love SM. But, if I need to carry more than 2 deco cylinders, I'm going BM."

Thats very common. Most OW side mount divers seem to be in agreement that normoxic depths are kind of the limit for side mount. 4 tanks are fine and great. More than that and the loss of real estate on your back starts to bite. Obviously there are folks who dive SM with more than 4 tanks, leashes help etc but generally speaking 4 tanks is where it starts to swing back to BM.