Independent Doubles!

[DaleC]

I have never understood the enjoyment of gambling myself but I think that, at a core level, it is because I do not consider myself a lucky person.
I do however think I'm kind of smart and i like to tinker. I derive a great deal of pleasure from being a Curious George. For me, diving and understanding different systems is fun. Not as fun as nooky perhaps - but still... fun

 

[DaleC]

Hey Sas, stop reading my mind!

 

[AndyNZ]

I am trying to think how this would be different for two manifold divers.

The main difference, if you have a left post failure (assuming regulator) the you isolate that reg, but you still have access to all of the gas in both tanks. You'd still have to buddy breathe but you've got (nominally) twice the gas that you would have if the donor was on independents.

Again, I am mostly thinking of it from 'cannot make a direct ascent' point of view.

When I ask MD divers why they choose to dive blind should they have a failure that causes the isolator to be closed and they have to breath the right post (no SPG) I am given the answer "it doesn't matter, either one has enough gas to get out or one doesn't." Seems like not too much concern about gas reserves there. What if their buddy goes OOG and they both have to breath off that reg? Would one rather be able to know how much gas is left or not.

It depends on the failure, essentially you are looking at something like a burst disk in the left post valve as being the kind of thing that means that you have to isolate and only have the option to breathe from the right post - in which case you're in the same situation.

If it's a left post reg issue, you close the left valve - sure, you lose the SPG but you still have access to all the gas.

With failures, whether single or multiple, you have to have a dose of realism - I've never seen a burst disk go apart from when a tank is being filled. I've seen some tank o-rings that start leaking when the pressure in the tank drops below some point - but again rare. There's not very much that would cause the situation you describe - the chances of the occurring in comparison with doubling up on HP hoses (HP hose rupture is fairly common, despite being mostly avoidable - apart from Miflex hoses that just go with no warning or indication)....?

Personally, I wouldn't be too worried in the situation you describe - I'm mostly diving in a team of 3, so our gas reserves are distributed between us and there is just more of it.

 

[AndyNZ]

I play around with different gear as much as I can. Sometimes I've had some horribly uncomfortable dives due to some bad setup I've dived with, but overall my changes to my gear as a result of experimenting has improved my comfort when diving a great deal.

I have to laugh at this, Sarah... but I am laughing at myself!

Five years ago, I was 100% anti-DIR, didn't believe that anyone could tell me what to do, that I had to work out for myself.

I'd pick an aspect of my gear, play with it, fiddle it, try different things and choose which seemed to work best. Despite digging in my heels at every step, my kit slowly became to resemble the DIR system. I looked at one day and just went &$@%#, how did this happen???

Purely by coincidence, the dive shop I was teaching for at the time was bought by two BSAC instructors, who had also done a lot of training with GUE. I had an opportunity to do Fundies, so I did - with the attitude that I wasn't going to adopt anything new, that my way worked. It was a very interesting experience - the reality is, there are shortcomings to using manifolded twins, but the shortcomings are worked around by procedural approaches. It's what people talk about in terms of the "holistic" system. I actually disagree that you have to adopt the whole system to be a better diver (have more fun!) and that if someone did cherry pick some things that suited them that it would benefit them as a diver. It's when you do start adopting everything, most of which is really a way of thinking, it just all fits together like the parts of an Aston Martin.

What I forget at times, is that whilst that is my journey, it isn't everyone's.... but even those you know will go down that path will need to do it in their own time.

So I laugh, but not meanly, but I am curious as to what your dive gear will be like in a couple of years time!!!

 

[Gombessa]

There is no risk to trying out different bits of scuba gear...

Well, I respect that you hold that position, but I'm sure you would agree that risk of discomfort during diving, or occasionally really screwing up something important like hose routing or trapping some piece of gear you didn't anticipate, or distracting you to the point where you're not as careful/aware of a buddy because you're fidgeting with a gear change issue, can be reasonably considered by some to be more substantial of a risk than that of wagering a single dollar on a improbable bet. But that's a bit beside the point. Anyone is free to tinker as they will, but when it comes to scuba for recreational enjoyment, finding a system that works and is proven safe and effective, and becoming well-versed in that system whatever it may be, has for many people a significant benefit above continually experimenting and changing positioning and defeating muscle memory on the off chance that they'll come across something better. I'm sure it's all open for debate, but for some people the risk/reward or effort/reward is different from what you state above.

 

[TheBigPhillyFish]

Alright, well I see we went off course for a little bit there. I hope no one has any hard feelings from this post or anything said in it.

But for you ID divers, I put my rig together today, strapped on a set of AL 80's and threw it on my back. And to be honest, doesnt feel any different then diving my single steel 133 with a pony bottle. But I can say it does seem a lot more organized then my single and a pony.

A few questions if you don't mind!

I was told by one of my LDS guys to install a 7' hose on my primary reg, which has my dive computer attached, a small SPG and the low pressure hose for the bc. Now he said in an OOA situation for a buddy, to remove my primary reg from my mouth with the 7' hose and pass it to my buddy, and for me to switch to the regulator on the 2nd tank. I was wondering your thoughts on that? After some careful thinking, does it matter which side the 7' hose is on? I am heading to the pool tomorrow just to try it on in the water and to figure out hose layouts. Another question, what about an octo, Is anyone still diving with an octo on one reg? I hear so much different opinion's about the octo. Its just gonna confuse you, why need it... Just curious what you guys think, or is it just better to use the two regs?

Another question. And I may need to be pointed in the right directions. I was thinking since my dive computer is air integrated and is on the left post, I would start on the left side for 1000 psi, then switch to the right and use that till it reaches 2000 psi and switch back to the left side for the last 1000 psi. Always keeping 1000 psi in each tank at the end of the dive. So I was wondering what everyone else is doing as far as gas usage?

Thanks for all the help!

 

[AndyNZ]

After some careful thinking, does it matter which side the 7' hose is on?

If you put it on your left post, and you decide to donate gas to someone, and you are in an overhead environment, and the tank valve contacts the ceiling and rolls shut... well your buddy is OOG and can do nothing about it. Whereas if you put it on the right post, and the same events occur... then you can reach around and open it because you'll know what is happening.

Of course, you also need to think about which post you put your primary inflation on.

In the event that the valve has completely jammed shut, and your primary inflation (wing) comes off your left post.... then you are screwed. If you put it on your right post, you can at least breath from the LPI oral inflate mouthpiece because it's connected to your right valve, which cannot roll shut.

 

[Gombessa]

Congrats on getting the setup up and running! Hope you have fun with it.

After some careful thinking, does it matter which side the 7' hose is on?

I think a lot of this depends on how you want your hose routing to work. Whether manifolded or independent, I'm thinking the "long hose on right" standard came about from the need of cave divers to not have the post connected to the donating hose roll off on a donee in an overhead. If you're not concerned about this, and have a way to route or stuff the hoses to your satisfaction complementary to your other gear, I'm sure you can find a way to route the long hose off either post.

 

[Sas]

I have to laugh at this, Sarah... but I am laughing at myself!

Five years ago, I was 100% anti-DIR, didn't believe that anyone could tell me what to do, that I had to work out for myself.

I'd pick an aspect of my gear, play with it, fiddle it, try different things and choose which seemed to work best. Despite digging in my heels at every step, my kit slowly became to resemble the DIR system. I looked at one day and just went &$@%#, how did this happen???

Well I have always listened to what people tell me to try out, but I reserve the final decision for myself. Even down to little things like I like having my SPG clipped on my shoulder d-ring rather than my hip. During a recent class my instructor said it is preferable to have it on my hip, so I dutifully did this for the course and a number of dives after to give it a fair go. In the end I preferred it on my shoulder a great deal more. That's just one little example but there are lots of others. I'm not anti-DIR, most of my gear is DIR compliant (and I get 'accused' of being DIR fairly regularly) but gear is only one part of DIR and I would guess that my personal philosophy is not really along DIR lines. I.e. I think personal preference should determine what gear one wears for the type of diving I do (I think at advanced levels there is a lot to be said for standardisation but I have no real ambition to do any diving like that). And my favourite diving is solo diving.

Purely by coincidence, the dive shop I was teaching for at the time was bought by two BSAC instructors, who had also done a lot of training with GUE. I had an opportunity to do Fundies, so I did - with the attitude that I wasn't going to adopt anything new, that my way worked. It was a very interesting experience - the reality is, there are shortcomings to using manifolded twins, but the shortcomings are worked around by procedural approaches. It's what people talk about in terms of the "holistic" system. I actually disagree that you have to adopt the whole system to be a better diver (have more fun!) and that if someone did cherry pick some things that suited them that it would benefit them as a diver. It's when you do start adopting everything, most of which is really a way of thinking, it just all fits together like the parts of an Aston Martin.

Well I plan to do Fundies too to see what it is like Have been looking into that recently. I have been doing courses with different instructors and different agencies where I can, to get a broad range of opinion.

So I laugh, but not meanly, but I am curious as to what your dive gear will be like in a couple of years time!!!

So am I! It has already changed quite radically over the nearly two years I have been diving but I think as you have done, it is something I am working out myself with a lot of input from others as suggestions and so forth. If I hadn't bothered trying new things, my setup would be a lot less comfortable than what I have now. The point is, I don't want to close my mind to suggestions and ideas. For example, I have manifolded twins as I prefer that setup to independents but I think it is personal preference and both have their place.

Well, I respect that you hold that position, but I'm sure you would agree that risk of discomfort during diving, or occasionally really screwing up something important like hose routing or trapping some piece of gear you didn't anticipate, or distracting you to the point where you're not as careful/aware of a buddy because you're fidgeting with a gear change issue, can be reasonably considered by some to be more substantial of a risk than that of wagering a single dollar on a improbable bet. But that's a bit beside the point. Anyone is free to tinker as they will, but when it comes to scuba for recreational enjoyment, finding a system that works and is proven safe and effective, and becoming well-versed in that system whatever it may be, has for many people a significant benefit above continually experimenting and changing positioning and defeating muscle memory on the off chance that they'll come across something better. I'm sure it's all open for debate, but for some people the risk/reward or effort/reward is different from what you state above.

Gombessa you quoted me out of context by not including the rest of what I said, which is unfair. I don't think one should put on new gear and start doing difficult dives where new gear could cause problems due to unfamiliarity or poor placement etc. By trying out I mean in controlled conditons, a pool, a shallow dive, etc. I try out a lot of new gear under a pier to see what I think, for example. And some things I plan not to change, as I am quite happy with how I have them now so it isn't about constantly changing gear just for the hell of it. It's about trying out new things to see if I can improve on them. If I can't I stick with what I've got.

 

[AndyNZ]

During a recent class my instructor said it is preferable to have it on my hip, so I dutifully did this for the course and a number of dives after to give it a fair go. In the end I preferred it on my shoulder a great deal more.

I was the same with the SPG, but I found it became a pain when carrying multiple stages.... it's part of that whole journey thing, what you did at the start doesn't often make sense until the end. Some people can just accept "this is the way it is", but I can't... and hated the "it will make sense when..." responses!

Well I plan to do Fundies too to see what it is like Have been looking into that recently. I have been doing courses with different instructors and different agencies where I can, to get a broad range of opinion.

It's a great course, and you're spoilt for choice with both Nick Schoeffler and Steve Trewavas right on your doorstep. I only know Nick on nodding terms, but has a good reputation, and Steve is plain awesome! Well, he is a New Zealander!!