35 replies to this topic

[WreckWench]

Karl you should have booked your Cozy trip via us...you would have saved money (we have buying clout of 6k) and you could have gotten 60 minute bottom times. (We are NEVER limited to 45 mins nor are the divers we book with them.)

Now to your comments...for many divers you are right...an aluminum 80 is all they will need and all they will ever use. However for divers who go beyond an alum 80 which is a small %...sidemount provides some very interesting and inexpensive options.

It requires VERY little add'l training (hence the talk about adding it to open water classes and its current inclusion in open water classes thus gaining very broad exposure) and it requires very little extra cost...the nylon bands are far cheaper than a set of bands or manifold and a bp&wing runs the same as a bc and the adpt is very inexpensive compared to a traditional double's set up. And to some its 'tech light' and to others its a way to dive doubles without all the expense of rental in places like Bonaire, Grenada and others that charge a small fortune to rent doubles. It is a serious diving protocol for cavers and now expanding to other forms of technical diving. It is also a way for those people wanting more gas/air to get it without having to go the doubles route. And whether you dive 2 80's as backmount and slung 80 or 2 slung 80's...its a viable option for those wanting or needing more than 80cf on their back.

Will it be as mainstream as nitrox? Probably not but then who would have thought that nitrox would ever reach its current level of popularity. Will it be more popular than rebreathers? Probably...as rebreathers are still very EXPENSIVE and still daunting for the average user. Sidemount is not daunting in the least...it is independant doubles very much the same as an 80 on the back and slung 80.

My point is the industry is moving on MANY levels towards offering sidemount in many applications and I've been fortunate enough to have early awareness/exposure to this trend. Will it be anything more than a fad? Maybe...maybe not. To base its future success on its current penetration is not appropriate as it is JUST gaining US and Global exposure now. Instructors are just getting certified to teach it. So the members of this site who have already been sidemount certified such as uwfan, georoc01, scubatooth are WAY AHEAD OF THE PACK...heck OTWDiver is continuously teaching classes to instructors...so its very to have a cert # ahead of most dive pros and yet not be a dive pro!

And for some this will be the first and only exposure they have to the topic and that is cool too! And for some it may be what they are looking for...also cool!

Will it replace traditional scuba as we know it? No but it gives you options that you have not previously had. And THAT is very cool! -ww

[secretsea18]

Finally, although I'm not a photographer, somehow I'm NOT seeing the shutterbugs fooling with BOTH their fancy/big photo/video rigs and then on top of all that doing the sidemount thing...just way too much machinery to fool with.

As a photographer, and as I said, there is no way I would want to be less streamlined, and have bulky tanks nor more dive crap to cart around.

I have a spare mask, too, but it is prescription and always left at the dive resort or on the boat .... I don't dive places where I would need it immediately... so I just return to the boat and get it.



What we all need are the gill implants.


Robin

[Capn Jack]

What we all need are the gill implants.

Robin

I would have lost the bet - I thought you'd already gotten a set of those...

[secretsea18]

What we all need are the gill implants.

Robin

I would have lost the bet - I thought you'd already gotten a set of those...

I continually search all the medical journals, and medical conferences for this innovation. For some reason, they are either SSI and kept that way by the military or the dive market is not putting in enough $$$ into research into this concept.... .... because they keep wanting folks to buy more certs to haul around more gear. (ducking)

Edited by secretsea18, 04 September 2010 - 12:26 PM.

[Scubatooth]

Robin

Another advantage of sidemount especially for photographers is the stability in the water. You really have to work to get out of flat trim. So if your trying to hold your position to get a shot that is a advantage to me.

As for tanks you can use any tank out there from 13 to 130 ft3. The way I have my rig set I can go from sidemount to back mount by putting a single tank adapter on back and go from with only changing out two bolts.

As for carrying two tanks it's for redundancy, trim but also gas. With Standard using one tank at a time if you follow "be back on the boat with 500psi" on a two tank trip your going to end up with 1000 psi or a third of a tank on the deck, where for the same two tanks after two dives I can take them down to 250 psi each and still have 500 when I get back on deck.

As for drag there isn't any more then a single tank rig in my comparison as the tanks are in your slipstream rather then out in the open adding to your profile in the water.

[ScubaHawk]

Rats! It's a thread about tank positions....Never mind

[Dive_Girl]

Rats! It's a thread about tank positions....Never mind

Hawk, you are simply a gem!

[Dive_Girl]

I beleive anytime new ways to do things are tried out in a recreation advancement occurs. If the originators of scuba equipment stopped at their first design, we wouldn't have the great choices in dive gear that we do. We wouldn't have BCs that connect to our regulators and allow us the ease of buoyancy at the push of a button, underwater lights, underwaters cameras, dpvs, fins that aren't just hunks of rubber, computers, pressure gauges, drysuits...you get my point.

I welcome change and embrace the opportunity to check much of it out first hand.

You have to look at the application for sidemount:

1. People who use a lot of air and need big tanks or multiple tanks
2. People who dive doubles
3. People who do technical diving
4. People who have injuries that normal tank configurations can not be used

You can add to that list being able to reduce previous dive limitations at remote dive locations. In the Pacific Northwest we have some incredible dive sites that I am unable to hike doubles into, but I can pack in side mount equipment and I can even drop the tank sizes based on my lower sac rate (I have sidemounted 72s and even 40s). Additionally, I can dive sidemount in place of doubles at locations traveled to where doubles are not available.

[WreckWench]

Great insight Nicole! Thank you!

Anyone else?

[duganalexzander]

I'll reawaken this thread, because I plan on diving sidemount for all the usual reasons (cave diving, redundancy [no buddy]), but for one which no one else has considered. I won't use a manifold, and I'll even tell you why.

I'm afraid of dying.

Little bit of background:

Manifolds are not mainstream in recreational diving, because rec diving doesn't really promote the use of multiple tanks. The exception to this is the SDI Solo Diver course which recommends a bailout bottle (no, spareair doesn't cut it. You need 30 ft^3, and you may as well spend the extra $20 for a 40 ft^3 with basically the same dimensional and buoyancy characteristics [PS. this info about SDI is from the solo diving presentation at BTS last weekend]).

So manifolds crop up in what is generally considered tech diving. (Thus, sport divers read on at your leisure, but i'm afraid you might be left out.)

I'd consider any tech diver to be of above average intelligence (and above average craziness). They have to be, as they use more complicated gear in more dangerous situations.

Now, as many of us have noticed, tech divers like redundancy. They have two regulators, two second stages, two tanks, some have two bladders in their wings, and they're supposed to have two computers (DIR/GUE are obvious exceptions). All of this redundancy is to cover someones butt when the @!&% hits the fan at 200'.

The problem I have with the manifold, is that it negates all of these redundant systems by creating a single point of failure (so I can't help but wonder why they're so popular). If you have a tank or regulator failure, you just isolate it w/your manifold and go back to the surface. Its annoying, maybe even a bit scary, but its not life threatening. Now, what happens if your manifold fails? Its connected to both your tanks, both your regulators, and both of your wings (for those that use redundant bladders). Then you're in trouble because if your manifold breaks, all your gas is gone. How are you going to get out of that one? One option is to go straight to the surface, maybe cutting deco and get bent (not my first choice); except...if you're doing cave diving or are deep inside of a wreck there's no straight shot to the surface. Thus, you run out of gas and drown.

Now, I realize that a manifold failure is unlikely, but so is a regulator failure and yet we still take precautions against that.
I've been diving since 2006, and I've suffered an air bladder failure and thats it. [To be fair, dad put my BC in the garage and a mouse chewed a hole in it to make a nest. I found this out at 40' when it was time to come up. Later, I found the hole hidden behind my shoulder...and I found the mouse.]

Additionally, I don't have eyes in the back of my head and (except for you mom divers), i'll bet vital parts of my anatomy that no one else on this forum does either. Nor, when we're all decked out in all our wet/drysuits, hoods, and everything else, can we really turn our heads enough to look at our manifold. Instead, we must approximate where the failure is by the flow of the bubbles. Left or Right? Then, is it a tank failure, a problem with my regulator, or a problem with a connection? Only real way to find this (that I know of, feel free to let me know if there are others), is to crank down that iso-manifold and check everything systematically until you find the problem.

One other thing to consider. How many of use use an air integrated computer? I do (or rather, my computer is mounted on my gas gage). Now, mine is a PITA to check things on because its on a demon retractor (you know, the kind that are hard to find, and pull so tight you need actual strength to extend them). So, if I want my depth, remaining gas, bottom time, estimated residual nitrogen, ect. I need to haul the thing out, focus on it, and read it. If i'm fast, I can get all that done in about 3-5 seconds. Again, times may well vary between us. I'm sure many of you are faster than I am, and i'm sure some are slower. Not saying there is anything wrong with either, but my personal preference is to do everything as quickly and efficiently as possible and so far thats not happening.

Now look at a sidemount setup. Tanks are nested at your sides, if there's a problem, you instantly know which tank it is. After a moment of quick analysis, you know if its a tank, a regulator, or a hose. Your tanks are independent, and because there is no manifold creating a single failure point you always have a backup. Your gas gages/integrated computers are there, on 6" hoses to the tanks, and can be positioned perfectly so you only need to glance to read them. If I have a regulator failure on one tank, then I just switch to the other tank. With proper gas management (which you should be practicing), you should be just fine. In the event that you maybe have not been good about which tank you suck on, and you find yourself with 300psi in one tank and 1500 psi in the tank that had a stage failure, then you can take a regulator off of your travel or deco gas and put it on the fuller tank.

If you have only the two sidemount bottles, then consider holding your breath and swapping tanks for your good reg. Its not a good solution, by any means, but I think its better than drowning. Can't say that i've tried it yet, but this summer i'll do it on the surface and see how long the switch takes.

Additionally, when cave diving or in an overhead environment, your tanks can hit the ceiling and i've heard of cases where the valve was shut down enough that ambient pressure made it very difficult to breath the regulator. In sidemount, you don't have that problem. Finally, the best part of side mount is...........


I don't hit my head on my damn regulator every time I look up!


Now, everything i've said so far has been focused on the solo diver. Clearly, most everyone here dives with a buddy. That being said, what if you have a manifold failure and your buddy (for some reason) only has one good regulator. Unlikely, but its always possible. In this case then you're in deep @!&%. With two independent doubles you are able to support yourself, by yourself, thus you make the dive safer for you and your buddy.

Thats my two bits. (though its closer to the whole dollar). Please, anyone or everyone, if you disagree with me then let me know. This is in the spirit of debate and safe diving practices, which I think we all enjoy.

If I've given some misinformation, then I apologize for making a mistake. Please point it out so myself and others can learn from it.

-Will

P.S. Sorry for any typos.

[peterbj7]

A question and some comments. The question - what do manifolds have to do with side-mount diving?

The comments. If you're diving completely separate tanks and a regulator goes awol you've generally lost access to all the gas in that tank. That's why we use manifolds, to keep that gas available for use. I have never experienced or heard of the catastrophic failure of a manifold. It's clearly theoretically possible, but I rate the likelihood comparable to that of the steering column on a car fracturing - certainly theoretically possible, but I've never heard of it.

Now, assuming your manifold doesn't just dematerialize it will probably fail either at one of the ends or at the isolation valve. I've certainly seen abused manifolds leaking at one of the ends after it's been used as a carrying handle for the twinset. But even so, such a failure is likely to be abundantly clear before the dive even starts, and if it wasn't as bad as that it's unlikely to progress to total failure during the dive.

The valve on a manifold isn't turned on and off very often so is likely to have a very long life, given a modicum of care and attention. Theoretically though it could fail in one of two ways - it could become impossible to turn, or it could blow up and blow out. If that latter were to happen you'd certainly have a problem, as you'd rapidly lose the contents of both tanks. But again, how likely is that if the equipment is even moderately maintained? The first failure is more likely but would only cause an actual problem if you then also had a regulator fail.

I'm sorry, a manifold is a simple piece of equipment that is easily maintained in perfect functioning condition. Any failure is unlikely to be without warning and catastrophic. Failure of a regulator is vastly more likely. You'll find that for many technical diving courses use of a manifold is mandatory.

But as I asked earlier, what does this have to do with side-mounts?

[duganalexzander]

OH. I really really should have added this earlier and I apologize for not doing so.

I'm not a tech diver, but I plan to be.

I have not used a manifold, however I have done some research on them. I try to think things out in a logical step by step progression, usually on a long car ride, and this method has served me very well on everything from midterms to a completely new thermal cooling system for a very overpriced computer. Honestly, after using the computer for a few days in the winter, I realized that I could put the heat sinks outside the PC and use it to heat my room instead.

I did have a lovely conversation with Steve Lewis (from TDI) about advantages of sidemount, and he strongly recommended that I not use manifolds because of my concerns about them. The added stress of the possibility of 'total system failure' would increase my gas consumption, and I may assume a manifold failure was happening before considering a more likely option (loose O-ring).

So, the purpose of this post was to state a few things I should have sooner, and politely request that I not be flayed alive for my fairly legitimate concerns about a popular diving system.

I'd love to hear about other advantages of manifolds. I know that it allows you to equalize your tank pressure, but I believe that proper gas management of independent doubles would almost negate the disadvantages of not being able to balance tanks.

-Will

[duganalexzander]

A question and some comments. The question - what do manifolds have to do with side-mount diving?

The comments. If you're diving completely separate tanks and a regulator goes awol you've generally lost access to all the gas in that tank. That's why we use manifolds, to keep that gas available for use. I have never experienced or heard of the catastrophic failure of a manifold. It's clearly theoretically possible, but I rate the likelihood comparable to that of the steering column on a car fracturing - certainly theoretically possible, but I've never heard of it.

Now, assuming your manifold doesn't just dematerialize it will probably fail either at one of the ends or at the isolation valve. I've certainly seen abused manifolds leaking at one of the ends after it's been used as a carrying handle for the twinset. But even so, such a failure is likely to be abundantly clear before the dive even starts, and if it wasn't as bad as that it's unlikely to progress to total failure during the dive.

The valve on a manifold isn't turned on and off very often so is likely to have a very long life, given a modicum of care and attention. Theoretically though it could fail in one of two ways - it could become impossible to turn, or it could blow up and blow out. If that latter were to happen you'd certainly have a problem, as you'd rapidly lose the contents of both tanks. But again, how likely is that if the equipment is even moderately maintained? The first failure is more likely but would only cause an actual problem if you then also had a regulator fail.

I'm sorry, a manifold is a simple piece of equipment that is easily maintained in perfect functioning condition. Any failure is unlikely to be without warning and catastrophic. Failure of a regulator is vastly more likely. You'll find that for many technical diving courses use of a manifold is mandatory.

But as I asked earlier, what does this have to do with side-mounts?

Sorry, the big question i've been wrestling with over the past few weeks was whether to go independent doubles or manifold. Seeing as sidemount is, by nature, independent doubles I thought it was a bit relevant.

Sorry if I went too far off topic.

[peterbj7]

I would be quite surprised if anyone from TDI were to recommend strongly against the use of manifolds.in absolute terms. Probably he was just trying to reassure you that there's more than one way of doing most things and that if one aspect really worries you there's probably a way around it. Certainly when I was an active IANTD instructor the use of a manifolded twinset was mandatory on all but the lowest level of technical diving. I can't believe they've dropped that requirement, and I'm pretty sure that TDI would follow the same rule. But obviously that only applies when a twinset is appropriate for the dive, which of course it isn't when sidemount techniques are being employed.

But I don't see why you're worried about manifolds. What failures of manifolds have you heard about?

[georoc01]

I'm with Peter here, in that when I did my tech training, we were diving with 4 tanks, two on our back, plus one on each side, with the sidemounted tanks being our higher O2 percentage tanks that we used during the deco stops on the way back to the surface.

When I did sidemount, you are now in the need of switching tanks regularly in order to keep the amount of gas relatively even between the two tanks, as much for balance as it is to keep your redundancy in place. So now you are going to have 4 tanks at your sides, two of which you are regularly switching from. Now, what are the odds of you grabbing the wrong reg and switching to a higher O2 tank?

When I did sidemount, I was doing my gas switches on my own. During my tech class, we we doing our gas switches in tandem to verify that your buddy/teammates didn't make the mistake above.

Given a choice of taking a chance at a manifold failure vs making a switch to the wrong gas at depth, I'll take the chance on the manifold.