Learn Doubles or Sidemount first?

[kafkaland]

I would look at the diving you will be doing, and the buddies you'll be diving with, in the near to mid term. If almost everyone is diving sidemount, let's say in the Mexican caves, go there and find a good instructor in that environment and configuration. If it's almost all backmount, like much cold-water wreck diving, do that. Dwelling on idiosyncratic differences in very unlikely failure modes shouldn't drive the decision.

 

[PfcAJ]

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.

Sure. I guess if you just go catatonic and do nothing any leak could kill you.

Meanwhile, in reality...

 

[broncobowsher]

This can quickly spin off into a manifold doubles vs. sidemount debate like 100 other threads. Having no meaning to the original poster searching for info.

So in the spirit of completely derailing this thread, there is also the Z-system where you can manifold you sidemount. The worst of both worlds? Like even more hoses strung across your chest?

I will also suggest trying both. Your basic classes are likely to start with backmount. But you may find sidemount to your liking, or you hate it. At which point the decision is made. Get a rebreather.

 

[Caveeagle]

One of my sets of double 104s I got from a very well known exploration diver and has a non isolated manifold. There are some that believe the point xtra valve is more of a liability than not.

Back to OP's topic..

BM doubles will get you up an running faster. **Presuming you have your sh1t half way together in BM singles.**

There is a well established (hogarthian) standard that works well for nearly all divers. Set this up with a tech butt plate for stage/ deco bottles and you will be in great shape for AN/DP, or TecXX or whatever you are in for.

Nothing wrong with going the SM route, but you should be prepared for a bit of work just getting settled in basic SM. Then addding stages makes things a bit fussy. Imho

 

[leadduck]

Sure. I guess if you just go catatonic and do nothing any leak could kill you.
Meanwhile, in reality...

Meanwhile, in reality failing to handle regulator freeflow at depth is the most frequent non-medical cause of diver fatalities in cold openwater divers in our region, although virtually everybody dives with two first stages on 2 or three valves. Too many even experienced divers are unable to close the correct valve in time when their life depends on it by lack of training and practice of these skills. Yet most dive backmount (singles or with manifold) and are convinced it's easier and more convenient than independent doubles, pony tanks or sidemount.
The point is backmount is only easy and convenient for them because they skip training and practice. If you do it properly (like you certainly do), then you need to perform a complex valve close/open procedure behind your head correctly and quickly under stress in order to survive, when a sidemounter simply switches regs and is perfectly safe.

 

[doctormike]

Meanwhile, in reality failing to handle regulator freeflow at depth is the most frequent non-medical cause of diver fatalities in cold openwater divers in our region, although virtually everybody dives with two first stages on 2 or three valves. Too many even experienced divers are unable to close the correct valve in time when their life depends on it by lack of training and practice of these skills. Yet most dive backmount (singles or with manifold) and are convinced it's easier and more convenient than independent doubles, pony tanks or sidemount.
The point is backmount is only easy and convenient for them because they skip training and practice. If you do it properly (like you certainly do), then you need to perform a complex valve close/open procedure behind your head correctly and quickly under stress in order to survive, when a sidemounter simply switches regs and is perfectly safe.

When I was diving OC, I really did like BM doubles. But using them - especially with a deco obligation - should come with the commitment to understand and practice emergency procedures. I would ALWAYS shut down the manifold first, and then try to figure out which side was leaking, when doing drills. Once you have closed the manifold, you are in the same situation as a SM diver - independent doubles, just breathe from the working tank.

But some people don't do that. And if those people are fumbling around trying to shut off the wrong regulator with the manifold open, it doesn't take long to lose all of their gas, especially if their tanks are already low.

Some people dive doubles long before they do tech training (I did). If you don't have a deco obligation, then there is no safety difference between doubles and single tank - yes you can lose all of your gas if you have a free flow and you don't think to close the manifold right away, but that's no different than the situation in single tank diving. If you dive doubles without the training and practice, you are just diving a big single tank.

 

[Bobby]

I am about to venture into tech diving. I plan on learning both SM and doubles. Will learning SM make it easier to learn doubles in the future?

No, both BM & SM have a learning curve and they are different. I dive BM, SM, & CCR, all three have similar however distinctly different skill sets. Whenever I go back to a configuration that I've not been in for a while I do warm up dives to get my skills dialed back in and practice emergency procedures.

Will learning SM teach me valuable buoyancy skills early on?

Not any more than BM will if you spend the time to hone your skills and have your emergency procedures dialed in.

What are your opinions?

IMHO, it is easier to have good trim in SM compared to BM. With either I have to pay attention to have my trim dialed in when I switch back and forth. With BM my tendency is to be slightly head up, with SM my tendency is to be slightly head down. I have to work at both to have it right.

You live in AL which is close to the Mill Pond. Edd Sorenson, whom owns Cave Adventurer's and teaches elusively in SM. There are other instructors that teach in BM, I believe Edd has other instructors that teach through his shop in BM, although I'm not positive on that.

IMHO, your decision will depend on what you are more focused on. Boat diving for wreck and ocean, or cave diving. I have done a lot of both SM & BM from a boat, both can be done, however BM is the easier choice. Many boats are not set up for SM, often the crew don't like to deal with SM on a boat, & many SM divers don't have the skills to be self sufficient on a boat. SM can be done from a boat and sometimes it is easier than BM however it takes more time and effort to acquire the skills to truly do it well and self sufficiently.

SM can make things easier when cave diving for a number of reasons. Getting gear to the water and walking are easier and lighter in SM are the main ones. The vast majority of SM divers don't go into SM passage. Today there is "off the shelf" SM gear that makes setting up and dialing in as easy if not easier than BM. When I started in SM there was not any "off the shelf" gear so we made it ourselves. That required a lot of trial and error which simply is not the case today.

Safety has been batted back and forth in this thread. IMHO they both have their risks and one is not more safe or unsafe than the other. Both require skills that come from practice and repetition.

It will also take practice to be efficient setting up and getting in your gear. I gear up fairly quickly in both and generally wait a bit while others start to gear up. Many SM divers take longer to gear up simply because they haven't practiced and learned to be efficient. Wrecks that are on their side, I've found, easier to dive in SM than BM. When I'm on boats that the captains know me, they will let me splash first. When that is the case I'm often half way down before the first BM diver is ready to splash. It does take practice, especially getting back on the boat in heavy seas without burdening the crew. IMHO, handing up cylinders because you can't get up the ladder on your own in SM, is putting a bigger burden on the crew.

 

[Marie13]

What is apparently local practice here is to clip SM (and deco/stage) tanks to a line hanging in the water.

I guess one question you have to ask yourself is if you’re flexible enough to reach your valves in BM doubles to do a valve drill. Someone told me he had to do yoga for something like a year before he was able to easily reach his valves.

Heck of a lot easier SM.

 

[doctormike]

What is apparently local practice here is to clip SM (and deco/stage) tanks to a line hanging in the water.

I guess one question you have to ask yourself is if you’re flexible enough to reach your valves in BM doubles to do a valve drill. Someone told me he had to do yoga for something like a year before he was able to easily reach his valves.

Heck of a lot easier SM.

There's always the "slob knob"..!

 

[PfcAJ]

Meanwhile, in reality failing to handle regulator freeflow at depth is the most frequent non-medical cause of diver fatalities in cold openwater divers in our region, although virtually everybody dives with two first stages on 2 or three valves. Too many even experienced divers are unable to close the correct valve in time when their life depends on it by lack of training and practice of these skills. Yet most dive backmount (singles or with manifold) and are convinced it's easier and more convenient than independent doubles, pony tanks or sidemount.
The point is backmount is only easy and convenient for them because they skip training and practice. If you do it properly (like you certainly do), then you need to perform a complex valve close/open procedure behind your head correctly and quickly under stress in order to survive, when a sidemounter simply switches regs and is perfectly safe.

So the move apparently is to select a gear config that seriously limits your gas supply in event of an issue in order to avoid having any skills.

Cool. Sounds great. 10/10.