So why is my LDS so excited about sidemount all of a sudden?

[DevonDiver]

OK, I embrace SM but how in the heck can you say all that is easier than my way? I put on my BC, I get into the water, dive and then get out of the water. I have assisted SM divers putting on their tanks in the water beside the boat. I would never do that in rough seas.

Tony, what you may (?) have encountered is inexperienced SM divers. The process for donning/doffing sidemount cylinders should be a matter of seconds - whether on the boat or in the water. New SM divers have to develop new muscle memory actions to enable that (even if they're already experience back-mounted divers).

I've seen plenty enough (new) back-mount divers struggle with manipulating their rigs... before they've spent enough time with the gear to get slick with it. As with all things, it takes some time to become fluid and swift. Until that time arrives, rough seas are best avoided, whatever gear solution you've opted for.

 

[TONY CHANEY]

Tony, what you may (?) have encountered is inexperienced SM divers. The process for donning/doffing sidemount cylinders should be a matter of seconds - whether on the boat or in the water. New SM divers have to develop new muscle memory actions to enable that (even if they're already experience back-mounted divers).

I've seen plenty enough (new) back-mount divers struggle with manipulating their rigs... before they've spent enough time with the gear to get slick with it. As with all things, it takes some time to become fluid and swift. Until that time arrives, rough seas are best avoided, whatever gear solution you've opted for.

One in mind was not that knew to SM. He had already taken his diving to full cave with SM and did an expedition to the caves in Mexico...other that that I agree with what you said. I just don't see SM very nessary on boat dives UNLESS you are planning wreck / cave diving. Not to piss off someone just my take on it.

 

[DevonDiver]

One in mind was not that knew to SM. He had already taken his diving to full cave with SM and did an expedition to the caves in Mexico...other that that I agree with what you said.

Gotta bear in mind the impact of different environments/gear etc.

I've done all my SM diving here in the Philippines. I couldn't go back to the UK and don dry-gloves and expect the same ease of use immediately... there'd be some re-tuning necessary.... and probably some re-configuration (larger bolt-snaps etc).

Cave diving in Mexico isn't boat diving in rough, cold water. It'd be natural to expect some (considerable?) difficulty and 'fluster-factor' initially when making the change in any given configuration.

I just don't see SM very nessary on boat dives UNLESS you are planning wreck / cave diving.

I don't think there is any 'necessity' for it... just a preference.

To be honest, sidemount isn't even a 'necessity' for most overhead environment divers - unless they form part of the relatively small sub-demographic who choose to operate within very confined environments.

I love sidemount. My preference is based upon my individual circumstances. Beyond those, I cannot judge others. I dive in tropical water, wearing the thinnest gloves and minimal exposure protection. I dive AL80 or AL100s, with AL40 or AL60 stages. The oceans are generally calm. The dive boats are small and have easy access and hard-working, fit crews who don't mind hauling tanks in/out of the water.

Some other preference factors, that I have:

I am also, invariably, responsible for other divers. Many of the dives are deep (25-40m), even if not into overhead. Copious supply of donate-able gas is a prime consideration - especially given variable and unpredictable diver/customer skill, awareness and air consumption.

Many of my dives are deep and long... borderline NDL dives, if not in actual deco. Sidemount provides for those gas needs, without the cost and logistics factor of having to arrange double tanks in a less developed country. The temptation to compromise and do some of those dives in singles has ceased to exist. Any LDS can supply the tanks I need. Any boat can support my dives (doubles might capsize some of the smaller boats I've dived from! LOL).

It's common practice here for the boat crews to load cylinders on the boats. That means I just have to set-up my sidemount tanks in the shop and hand them over for loading. I wander out to the boat in my wetsuit; wearing my sidemount BCD only... fins clipped off through the bungees, mask on forehead (LOL). Sit on the boat for a short while enjoying a cool drink... then once anchored, hop into the water and get my tanks handed down to me. It's truly joyful... and a saving grace for someone whose body was subjected to the rigors of decades of rugby, martial arts and military service

For those reasons, I choose to dive sidemount on most occasions... and I can't help but recommend it for anyone in similar circumstances.

 

[TONY CHANEY]

Any boat can support my dives (doubles might capsize some of the smaller boats I've dived from! LOL).

It's common practice here for the boat crews to load cylinders on the boats. That means I just have to set-up my sidemount tanks in the shop and hand them over for loading. I wander out to the boat in my wetsuit; wearing my sidemount BCD only... fins clipped off through the bungees, mask on forehead (LOL). Sit on the boat for a short while enjoying a cool drink... then once anchored, hop into the water and get my tanks handed down to me. It's truly joyful... and a saving grace for someone whose body was subjected to the rigors of decades of rugby, martial arts and military service

For those reasons, I choose to dive sidemount on most occasions... and I can't help but recommend it for anyone in similar circumstances.

I am with you and the reason I am setting up a SM is when going to countries where doubles are hard to find i can travel lighter and still perform tec. dives.

 

[Sol]

Once again, thanks to all for your informative and helpful posts. From what I've gathered, everyone using / advocating sidemount for rec diving seems to have a different approach. With fewer than 50 dives, I'm in no position to judge what's valid and what's not, although I've found the discussion very enlightening, especially the observations about the economic pressures facing the dive industry and individual LDSs.

Far as I can see, sidemount makes the transition from single tank to double tank easier and perhaps less expensive, but it's got nothing to do with tec vs. rec. But at this stage I'm nowhere near ready for doubles, let alone caves.

Does this make sense to you folks?

 

[DevonDiver]

... at this stage I'm nowhere near ready for doubles, let alone caves.

It makes sense to have your core scuba skills dialled down to an instinctive level before progressing onto more complex equipment, or onto more challenging dives. That's good advice for any progression in your diving... even adding an underwater camera..

That said, sidemount can be very intuitive. PADI have recently authorized that even Open Water course can now be taught on sidemount (a bit ambitious IMHO, but you get the drift).

It's not harder, or more advanced... just different.

Caves are a very different matter

 

[Diver0001]

I'm considering side mount for two (well, two-and-a-half) reasons:

I would like to be so bold as to give very direct feedback:

1: Better trim. The folks I've dove with who have used both and now dive SM say trim is better SM. makes sense to me; two weights (tanks), one on each side, seems inherently more stable than one weight (twinset) concentrated on the midline -- less tendency to roll.

Trim/buoyancy are skills issues. If you're struggling with this then you don't need new gear... you need to improve skills. I've said it many times (and it's true) that I can look fabulous in literally any gear config. People who have seen me in various different set ups will confirm this. For example, last summer I dove in Vancouver with TS&M and PeterGuy in gear (aside from my own mask) that I had never seen before and I looked (I think) pretty darned good in it. The point being here that if you think you need new gear to solve a skills issue then you're on the wrong track. Skills are important. Gear is not.

2: Independent gas supplies. In SM the two cylinders are completely independent. True, you can shut down the isolater on a twinset, but one less thing to hassle with in a gas emergency. True, you don't have the option of using the gas in both tanks in the event of a reg failure, but true independence seems worth it.

Dude.... With backmount twins you can go both ways (open/close isolator) but with sidemount twins you're stuck jumping through hoops on every dive. Moreover, a double regulator failure on back-mount twins has the same effect as a double regulator failure on sidemount. A SINGLE reg failure on backmount, however means that you can still access all of your gas. A SINGLE reg failure on sidemount means that 1/2 of your gas just became inaccessible. In other words, independent twins INCREASES risk.... and no amount of thinking you look cool will change that...... There can be no question about that. Why do you think manifolded twins were invented to begin with? Hint: it was precisely to manage this risk.

2.5: I have poor shoulder mobility so valve drills are tough for me. If I ever had to do a valve shutdown in a real emergency, I'm not convinced I could get it done in time. I like the idea of having the valves right in front of me.

I can appreciate this point and this might be (for you) a valid reason to use side-mount or inverted twins. Having said that, however, I believe that many people who have trouble with shut-downs are having skills issues. Not all. Physical impairments are real and relevant. As an instructor I would just want to verify that this is really the case before looking for an out-of-the-box solution.

Enough people are diving SM who aren't wriggling through silty little holes and who aren't selling gear that I don't think all of them are just trying to look cool.

My impression too. Colleagues tell me that they want to give side-mount lessons because they can sell more gear and get students energized about a possible paradigm shift. To me, just *selling crap* is not an adequate reason to give a course. Personally I'm more conservative (and I don't have problems attracting students who want to improve their skills). I'd rather teach them *relevant* diving skills and refer them to a sidemount instructor when I see that they have a physical disability. For the rest, I can train them to do a lot (especially wrecks) in doubles. I've seen a few wrecks that were hard to navigate in back mount but I'm going to say that not a single one of those wrecks could have been navigated any more easily in side-mount. Aside from caves I have trouble seeing an application.

R..

 

[halocline]

2: Independent gas supplies. In SM the two cylinders are completely independent. True, you can shut down the isolater on a twinset, but one less thing to hassle with in a gas emergency. True, you don't have the option of using the gas in both tanks in the event of a reg failure, but true independence seems worth it.

It's way more complicated than that. You have to look at the likelihood of specific failures and the consequences. Manifolded doubles present some very significant advantages; one is that the gas is automatically, evenly distributed, leaving you with the best possible distribution in case of loss of one tank. The biggie, though, is the regulator issue. Reg failures are several orders of magnitude more common than pre-seat tank valve problems. The o-ring between reg and tank valve is like a reg failure; shut down the valve and you still have access to the gas in the tank.

Isolator failure that results in catastrophic gas loss is more-or-less unheard of in the real world. Even if one side of the isolator failed, you could still shut the iso and only lose gas in one tank. But two regulator failures is far more likely than an isolator failure to begin with, and obviously that presents the same problem in both independent and manifolded doubles.

There is a theoretical advantage to being able to see and effortlessly handle the valves, I can certainly understand that, but don't fool yourself thinking that independent doubles are 'safer' than manifolded.

 

[USFpsychDiver]

I appreciate the comments here. I continue to work on my trim in BM, and it does need additional work, work that, at this point, I don't intend to try to solve with gear. However, while I don't know that SM is inherently more stable than BM, because I haven't dove both, highly experienced divers I know who've used both say that SM trims out better, and it logically makes sense, having that tank weight distributed laterally rather than medially. To say that everything is 'skills' and nothing is gear ignores that fact that gear improvements do make a difference (should we all go back to horse collar BCs?). I also ski, have skied for decades. When I started we used leather boots, cable bindings, and long straight wood skis. These were great for go-fast but not so much for making quick, tight turns. Today's gear is much better for making quick, short, controlled turns. True, you can't but new skis on a novice skier and suddenly they'll be able to ski the double-blacks -- skill and training is necessary -- but the gear does make a difference.

Was supposed to go dive the lake this week to work on buoyancy and trim and practice line valve drills but my buddy had health issues and couldn't go.

 

[TSandM]

Two comments:

One is that dive shops face a difficult problem, because once you have acquired all of your necessary equipment for diving, your purchases fall off in number and size. Selling a new BC most likely involves attracting an entirely new customer, which is the most difficult part of retail. Selling to people whose names you already have, and who have already indicated an interest in the sport, is far easier. But how do you convince a diver to replace gear he has that is working? Only by convincing him that you have something he'd like even better. Sidemount offers a big opportunity here, because it's appealing to the people who might have thought about diving doubles, but balked at the expense of buying manifolded doubles, or feared the weight of the doubled tanks. It can also appeal to those who have ALREADY gone to backmounted doubles, as a different approach to market to a group which has already proven its willingness to spend large sums of money on diving. Pitch sidemount -- sell gear and training. What's not to like?

The second is the comment that trim is easier in sidemount. Trim is easy in any equipment, just as Diver0001 said above, if the equipment is roughly balanced, and the diver's posture is good. Here I am in backmount, and that's pretty decent trim:

What IS true of sidemount, in my very limited experience of it, is that you are more stable in a wider variety of attitudes in the water, if you can get the center of mass of the tanks aligned with the center of gravity of the tank/diver unit. In other words, you can point yourself 45 degrees head-down and stay that way; if I go 45 degrees head-down in backmounted doubles, I will do a headstand if I don't kick. But it takes a fair bit of kit-futzing to get a sidemount rig set up so that it is that stable for you, and it changes each time you change tanks. With backmounted doubles, I have one decision to make -- how much weight do I need to hang off the bottom bolt to balance?