Question Sidemount or backmount doubles?

[tbone1004]

Thanks. I just saw his comment. I definitely stand behind my comment. Any instructor who teaches you need less bailout than you’d need gas in oc scares me. Going into ccr I heard the old wives tales that it’s true. But after taking classes I learned it’s completely inaccurate
Edit: my comment was also biased some because almost all of my dives on ccr are cave dives but even if I was ow diving it would likely still be a deco dive which creates an artificial overhead.

I did say it in my comment but there does hit a point where you are carrying less gas on a CCR for cave diving, but we are certainly talking about what I would define as "extreme" cave dives in terms of depth and penetration, read 3-4 stage bottle territory and at that point you are one bottle ahead of where you would be without the CCR but there are only a handful that are doing that even within the cave exploration teams.

 

[Heat Miser]

I am not CCR certified, but the reasoning of @mdwalter seems acceptable to me. Could you please explain me where he is wrong? Thanks a lot!

Planning enough gas for a hypercapnic event, means that the two aren't that dissimilar. BO from CCR assume a 45 ltr/min SAC for 10 maybe 15 min.

 

[Subcooled]

I am an AOW diver that wants more bottom time and thus more breathing gas. For single-tank dives, I really like my backplate & wing setup. No issues with that for those kinds of dives. But I would really love to get some more bottom time and expand my reach/range. I will definitely seek proper training to go beyond my current certification in terms of maximum depth and no-deco limits. But with which setup?

I have scoured these forums and the internet for objective pros and cons for sidemount and backmount setups. (‘Objective’ being the operative word here. Most comments seem to be very much in favour of either sidemount or backmount diving.)

Even though I will not be cave diving or doing penetrations into particularly tight spaces - for which sidemount was originally developed - there are some benefits to sidemount that look very appealing to me. Here’s what I found, or at least the major differences between the two setups.

Backmount:

• One stable unit, preferred on boats (?)
• Quite heavy to log around on dry land (I don’t have the strongest back in the world)
• Not as streamlined as sidemount (?), but adding stage bottles doesn’t hurt streamlining further

Sidemount:

• Two units, may not be as stable on boats if tanks are donned above water
• Tanks can be hauled separately
• Sleeker in the water (?), but adding stage bottles negates this advantage somewhat
• Valves are easier to reach, and visible

A few questions regarding these two lists:

• Anything I missed on either list? There are some question marks in there, any comment on those?

If you loose balance and try to correct it, then the torque caused by heavy backmount doubles will break your ankles or knees (I have seen this happen). Sidemount kits have a lower center of mass and are thus more comfy when you stumble or fall on dry land (done that). It's also much nicer to drop one sidemount tank on your toe than to drop two + backplate (my friend smashed his toe with BM). Sidemount is better on ladders as it doesn't pull you back. Sidemount allows for a flexible back, which is quite a delight.

Backmount systems offer many benefits too, it's all about what kind of diving you want to do...

 

[Celt]

I sold all my sidemount gear last week. After trying it for 3 years I found sidemount is a very poor substitute for backmount. A lot of fuss for no gain.

 

[Doby45]

I sold all my sidemount gear last week. After trying it for 3 years I found sidemount is a very poor substitute for backmount. A lot of fuss for no gain.

A different tool for a different job. If all you ever do is nail all your floor planks down, you would not need a screwdriver. If all you ever do is screw down your floor planks, then a hammer might not be as useful. But, just because you don't use one tool or the other does not make that specific tool useless.

 

[broncobowsher]

I sold all my sidemount gear last week. After trying it for 3 years I found sidemount is a very poor substitute for backmount. A lot of fuss for no gain.

My sidemount went away after getting the rebreather. Kept the tanks and regs, but the rest was sold off.

 

[SlugLife]

I sold all my sidemount gear last week. After trying it for 3 years I found sidemount is a very poor substitute for backmount. A lot of fuss for no gain.

A different tool for a different job. If all you ever do is nail all your floor planks down, you would not need a screwdriver. If all you ever do is screw down your floor planks, then a hammer might not be as useful. But, just because you don't use one tool or the other does not make that specific tool useless.

Sidemount definitely has it's challenges, and I can understand why it doesn't work for some people. That's very different from saying SM itself is good or bad.

My own experience with SM is it had a much steeper learning curve, but overall I like it a lot more, and it works for me. I can see how backmount is certainly more if a "put on harness and go" option, and much better for other people, with other preferences, or other types of diving.

 

[Celt]

Sidemount definitely has it's challenges, and I can understand why it doesn't work for some people. That's very different from saying SM itself is good or bad.

My own experience with SM is it had a much steeper learning curve, but overall I like it a lot more, and it works for me. I can see how backmount is certainly more if a "put on harness and go" option, and much better for other people, with other preferences, or other types of diving.

I found handling the tanks separately was a plus. Swimming in the water when trimmed out nicely was also great especially for photography. But for me when I had to work on the bottom the tanks were in my way and not secure enough. Walking with 2 tanks swinging from shoulder d rings required steadying them with my elbows. What really put me off sidemount is when deep I had to detune both regs to be certain they weren't free flowing when working or digging in the silt. I like my regs on the edge of freeflow especially deep. But I now need to come up with some way to get my heavy twinset back in the boat.

 

[Celt]

My sidemount went away after getting the rebreather. Kept the tanks and regs, but the rest was sold off.

Yeah I kept the regs as they were my old ones. I couldn't think of any use for the short hoses and harness so I sold them.

 

[SlugLife]

I found handling the tanks separately was a plus. Swimming in the water when trimmed out nicely was also great especially for photography. But for me when I had to work on the bottom the tanks were in my way and not secure enough. Walking with 2 tanks swinging from shoulder d rings required steadying them with my elbows. (2) What really put me off sidemount is when deep I had to detune both regs to be certain they weren't free flowing when working or digging in the silt. I like my regs on the edge of freeflow especially deep. But I now need to come up with some way to get my heavy twinset back in the boat.

With SideMount, you can often carry each tank independently, and can even don or doff tanks in the water. I practically NEVER walk with 2 tanks swinging from d-rings, any more than a couple feet into the water. Did your situation require you to carry them both at the same time?