Learn Doubles or Sidemount first?

[Chris H]

+ Single LP50s are a breeze to move about.

Double backmount 50s are also a breeze to move.
I did mostly backmount OC, and recently picked up some LP85s and an SMS75. I think backmount is easier, and as others have noted, it really depends on what you want to accomplish. I'm sure Advanced Trimix dives can be done in sidemount, but at this point if I'm doing Advanced Trimix level dives, I'm sidemounting bailout on my rebreather. Sidemount certainly has its place.

 

[Dirty-Dog]

I don't dive SM myself, but one advantage if you like to do a lot of tech diving while traveling is that you can bring your rigging and get a couple of AL80s anywhere. Whereas it may be harder to rent doubles.

This was one of the primary factors that led me to go sidemount.

Doubles are easier to deal with off boats, SM is great in caves.

Backmounted doubles may be easier to deal with off boats. Sometimes. Sometimes sidemount can be easier. Along with availability, one of the other reasons I started with sidemount was weight. My first purely sidemount trip was shortly after I'd finished 6 months of chemo and radiation, and I literally didn't think I'd be able to stand up on the boat with backmounted doubles. But having tanks passed to me in the water was easy.

One other advantage of manifolded BM doubles is that if you have a first or second stage reg failure, you still have easy access to all of your gas. I have heard that there is some kind of SM manifold, but I don’t think that they are commonly used.

There is. It doesn't seem to be very common at all. I've never used one, nor do I know anyone who has, but I'm sure there has to be at least one person here who has tried it out.

If you have a reg failure in SM, I suppose you could move your working reg to the other tank and service it after the dive, but if you had no other source of breathing gas that might be a tough switch.

If you've planned your dive properly and are following the plan, you'll always have enough gas to get out on either tank.

 

[wetb4igetinthewater]

.If you've planned your dive properly and are following the plan, you'll always have enough gas to get out on either tank.

And you can easily feather the tank with the issue. Easy to manage.

 

[PfcAJ]

If you've planned your dive properly and are following the plan, you'll always have enough gas to get out on either tank.

You *should* have enough, but often when things go sideways unforeseen delays and issues can pop up. The manifold gives you access to all that gas rather than half of it.

 

[divezonescuba]

Some tec instructors will not allow you to start tec training with sidemount unless you have some sort of sidemount training already.

That can come in the form of a rec sidemount course or something like the PADI sidemount tec course which teaches you sidemount with deco cylinders, but no decompression or more complicated tec subjects.

Again, speaking from a PADI perspective, it is possible to get tec certs at the same time while doing the tec sidemount cert. however, it is like taking two courses at the same time with what should already be a difficult and intense course.

A thought is that a backmount tec certified diver would only have to learn / train for sidemount. Being able to see your valves and not having to deal with the manifold is way easier. It would be more complicated to be sidemount certified and then try to become proficient on backmount. The tec malfunction drills on backmount are way more complicated than sidemount, particularly since you cannot see your valves and backmount is not as stable as sidemount.

One of the most establish sidemount instructors in the world told me that a diver certified in a sidemount tec configuration would be crazy to do a backmount tec dive without backmount training.

 

[Dirty-Dog]

You *should* have enough, but often when things go sideways unforeseen delays and issues can pop up. The manifold gives you access to all that gas rather than half of it.

Sure, but if we're going for extremely unlikely scenarios, it's also true that there are failures which would require you to shut off your manifold valve (if there weren't, the manifold value would not be in use...), in which case you wouldn't have access to 'all that gas' in back mount either. In most cases, you could still access the gas in your "failed" side mount tank by feathering the valve. And yes, you can feather the valves when back mounted, too. But it's definitely not as easy.
Basically, I think the inherent risks diving side mount or back mount are essentially identical.

As for which to learn first (which is what we're supposed to be discussing here, after all...) I'd say whichever is easier to find an instructor for, in your area. Or a mentor. I am not aware of any back mount doubles certification (assuming you're using them on recreational dives). And although side mount certifications exist, I do not think they're actually required. I have never been asked to show a side mount card, which is good. I've got around 100 dives in side mount (I'd have to check to be more exact, but close enough...) but no card.

 

[broncobowsher]

I started on backmount. While there was plenty of good with it I didn't like the monkey on my back feeling. Valve drills were also a stretch for me. After borrowed tanks for training I started shopping around. Others I dive with were doing sidemount. Got a quick demo, saw some benefits, went that way. On a boat you are wide, but upright and not hunch backed. It's easier to pick up tanks when you travel (just grab a couple singles). But the hose origami in front of you can get overwhelming. You will invent your own version of a sideways giant stride. They are apples to oranges. So I went bananas, got a rebreather. If you are planning to get into trimix, you will eventually be looking at one anyway.

 

[leadduck]

You *should* have enough, but often when things go sideways unforeseen delays and issues can pop up. The manifold gives you access to all that gas rather than half of it.

You *should* have enough, but often when things go sideways unforeseen delays and issues can pop up. The manifold gives you the opportunity to loose all your gas rather than half of it.

 

[PfcAJ]

You *should* have enough, but often when things go sideways unforeseen delays and issues can pop up. The manifold gives you the opportunity to loose all your gas rather than half of it.

Ah yes, the fabled manifold failure that literally never happens. Reg issues otoh are common.

 

[leadduck]

Ah yes, the fabled manifold failure that literally never happens. Reg issues otoh are common.

manifold failure is a straw man, that one's unlikely.

No matter why there's a leak and where it is: The manifold gives you the opportunity to loose all your gas rather than half of it.