Question Rec cold water diver: Single, Double or Sidemount? (focus on safety)

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halocline

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General intention:
  • I want to dive (more or less) full year in local rivers and lakes.
  • Pure recreational diving.
  • Safety is priority number 1. Only diving with a buddy (or in a small group), never single.
You are a self described recreational diver with no interest in technical diving, and you want to be as safe as possible diving recreationally in cold water. The clear answer IMO is single tank with a good sealed regulator, good cold water technique, and a reliable buddy. You might consider a pony bottle, but it should not be necessary. It might make you feel safer, but it's unlikely it actually is safer, at least statistically. I'm not saying its a bad idea, but among the potential dangers in recreational diving, running out of available air should never be one of them. This is what gas management, buddies, and immediate access to the surface are for. Both are basic fundamental tenants of recreational diving.

Safety is based on diver judgement and behavior, and especially partnering with other safety-minded divers. Equipment is really not the issue here, other than making sure your gear is in good condition and reliable. Simplicity in set up and your familiarity and ability to manage the gear are probably the most important factors. One thing I would suggest is that you have some redundancy or contingency in buoyancy; likely a drysuit, which you may have mentioned and it flew by me, because cold water divers will eventually be in drysuits or they will quit diving in cold water. Nobody likes freezing. But if you're diving wet and you are using a lot of weight, make sure it's possible to ditch enough to swim to the surface and maintain control on the surface in the event your BC fails.

There is no reason to go for double tanks, either backmount or sidemount, unless you are interested in technical diving, and that comes along with technical training, part of which will be managing the new, more complicated gear arrangement.

I admit I haven't read this whole thread, but I see that some people are just encouraging you to dive like they do. Not always the best advice.
 

ginti

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I agree with @halocline

but needing new gear anyway, I can directly invest in a double tank wing BCD such as the XDeep NX Project.
Don't buy new stuff before a good discussion with a capable instructor (or, even better, more than one). He will help you understand what you need - maybe a single 15l will be ok in your case, or maybe you'll realize you want to go for tech or something else. Don't rush it :)
 

Lorenzoid

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I didn't read this entire thread ….
One thing we learned in this thread is that ponies are not common in the OP’s region.

Sorry to repeat myself, but I believe he would do best to address this kind of diving the way others who dive there do. If recreational backmount doubles are not an uncommon solution, go for it.
 

SlugLife

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One thing we learned in this thread is that ponies are not common in the OP’s region.

Sorry to repeat myself, but I believe he would do best to address this kind of diving the way others who dive there do. If recreational backmount doubles are not an uncommon solution, go for it.
So, choose diving and equipment based on what is common? I think that's a terrible principle.

There are many reasons why someone does, or doesn't do something. For example, maybe people don't carry pony bottles because they can't afford them, or because they're embarrassed, lazy, not aware of them, or their dive-buddy is super-reliable, or naïve, or safety-third, or practiced CESA, or because they have other redundant air, or perhaps dozens of other personal reasons. There are so many reasons why a diver doesn't carry a pony bottle, and the majority of those reasons are NOT good reasons to discourage another diver potentially interested in carrying one for their personal safety.

People should do what is best for themselves and their situation. And one-size-fits-all, is often NOT best for the individual. Sure, maybe a pony is or isn't the best option for the OP, but appealing to popularity as the basis for decision making just seem extremely unwise.
 

Marie13

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So, choose diving and equipment based on what is common? I think that's a terrible principle.

There are many reasons why someone does, or doesn't do something. For example, maybe people don't carry pony bottles because they can't afford them, or because they're embarrassed, lazy, not aware of them, or their dive-buddy is super-reliable, or naïve, or safety-third, or practiced CESA, or because they have other redundant air, or perhaps dozens of other personal reasons. There are so many reasons why a diver doesn't carry a pony bottle, and the majority of those reasons are NOT good reasons to discourage another diver potentially interested in carrying one for their personal safety.

People should do what is best for themselves and their situation. And one-size-fits-all, is often NOT best for the individual. Sure, maybe a pony is or isn't the best option for the OP, but appealing to popularity as the basis for decision making just seem extremely unwise.
Are you the one who deliberately dives with a mismatched SM set up with two different sized tanks?
 

SlugLife

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Are you the one who deliberately dives with a mismatched SM set up with two different sized tanks?
edit (I had a reading failure, see a couple posts down)

That's a blatant strawman. Safety is a real reason. Common is not. What I said holds.

Common/Uncommon may hint something problematic about the uncommon, but if someone wants to argue that pony-bottles are dangerous, go for it. I'm fairly sure the #1 and #2 reasons most people don't carry redundant-air is (a) they don't want to spend the money on one, or (b) some sort of laziness or disliking the bulk of carrying one.

If I'm to apply this "is it common" principle, I should give up on having ANY redundant gas at all. I think locally, I've only seen a pony bottle once, and never sidemount or any other redundant air. "I can't have any emergency gas, because .... well, I have to be like everyone else!" So, you're suggesting I'm the moron who carries redundant gas, because nobody else does?
 

SlugLife

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lemmings.JPG
 

SlugLife

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Are you the one who deliberately dives with a mismatched SM set up with two different sized tanks?
You forgot 2 different gasses, that will average out during the dive.
I just noticed my own reading comprehension failure of Marie's posts. I got 2 posts blended together in my head. I blame it on lack of coffee. Sorry about that.

So, yes. While I don't propose others follow in my foot-steps, I do sometimes "monkey-mount" AL80 left, and (mostly unused) AL19 right. The basic idea is to reduce the effort of dealing with 2x full sized tanks on every SM dive. It's not bad in terms of left/right balance and trim, you'll notice it, but it doesn't bother me. 2x AL50s is certainly better for that, if one can fit that into their budget (fill costs, more tanks, etc).

But no, I would never think 2 different gasses averages out during a dive, that's just really stupid and dangerous. Sidemounting 2 different gasses sounds like an accident waiting to happen.
 

MrVegas

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Two sets and your good to go. Even if they do only go to 2400 still about the same as the common 80.

Of course, you are correct, more tanks are the solution to any problem. I think I need to get my tank breeding program under control, though.
 
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