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luis
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Re: Consider a New (Maybe Better) Direction

Thu Dec 12, 2013 10:57 pm

SurfLung wrote:-

I was thinking of non-compressible flotation like cork or maybe that dense foam insulation that comes in sheet like plywood. If its' non-compressible like your body tissues, it's buoyancy wouldn't change with depth.
That is why I suggested a small diameter PVC pipe full of air. You can make it the length required for the fixed buoyancy you are trying to offset. You cap both ends and you end up with a truly non-compressible, fixed volume, buoyant, streamlined tube.

You can fit it in the depression between a set of doubles to keep it streamlined.


The Dacor Nautilus that is shown in the picture posted by Nemrod is a huge monstrosity. It is a very interesting idea (I bought one a few years ago to play with), but it is huge. I am not sure I know the exact capacity, but I would guess that it is easily 40 Lbs or more.


My suggestion with the PVC pipe is to offset a relatively small weight (5 to 10 Lbs), but you can make it any volume you like and you can adjust it.
Luis

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Mistralopitheque
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Re: Consider a New (Maybe Better) Direction

Fri Dec 13, 2013 12:15 pm

Interesting thread!
My idea of tackling the BCD requirement in a minimalist way is to have it built into my wetsuit.
I don't know if you ever seen them in the US, but here in Europe they were pretty common in the 80's and early nineties. Just imagine a neoprene pocket glued into the back section of your wetsuit, with attached direct system/oral inflator.
That's what I had built into my "Cousteau Odyssee"-Style Wetsuit. If I don't need the system, I can screw off the hose an close the hole with a blank-plug.
I spoke with some of the Cousteau veterans about the weighting techniques they used back then, diving at any depth without any BCD.
It is feasible, but requires some tricks and tweaks that are not always practical to implement in the kind of diving we do.
Finally, lets be honest: BCDs rule as soon as you're having to wear thicker neoprene or go deeper (which is how I usually end up).
Neoprene compression is a bitch. You can counter it with lung volume, but beyond a certain point its uncomfortable or requires you to use the kind of tricks and tweaks the Cousteau team used.

(I spoke with some of the Cousteau veterans about the weighting techniques they used back then, allowing them to dive at any depth without any BCD: Weight baskets at 30ft, taking up stones from the bottom...etc. Nothing you saw on screen, but it was there. Something that is not always practical to implement in the kind of diving we do)
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luis
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Re: Consider a New (Maybe Better) Direction

Fri Dec 13, 2013 1:36 pm

Mistralopitheque wrote:Interesting thread!
My idea of tackling the BCD requirement in a minimalist way is to have it built into my wetsuit.
I don't know if you ever seen them in the US, but here in Europe they were pretty common in the 80's and early nineties. Just imagine a neoprene pocket glued into the back section of your wetsuit, with attached direct system/oral inflator.
That's what I had built into my "Cousteau Odyssee"-Style Wetsuit. If I don't need the system, I can screw off the hose an close the hole with a blank-plug.
I spoke with some of the Cousteau veterans about the weighting techniques they used back then, diving at any depth without any BCD.
It is feasible, but requires some tricks and tweaks that are not always practical to implement in the kind of diving we do.
Finally, lets be honest: BCDs rule as soon as you're having to wear thicker neoprene or go deeper (which is how I usually end up).
Neoprene compression is a bitch. You can counter it with lung volume, but beyond a certain point its uncomfortable or requires you to use the kind of tricks and tweaks the Cousteau team used.

(I spoke with some of the Cousteau veterans about the weighting techniques they used back then, allowing them to dive at any depth without any BCD: Weight baskets at 30ft, taking up stones from the bottom...etc. Nothing you saw on screen, but it was there. Something that is not always practical to implement in the kind of diving we do)

I dove recently with a dive operator in PR that had a weight basket at 20ft for the customers to adjust their weights. I thought that was very nice.


I heard of an outfit in Oregon (or somewhere around there) that made wet suits with built in buoyancy bladder on the back. The only issue I see with that is that when you put air in the bladder it may push your tank away from you. That could be an issue with a double hose regulator.

It is an interesting idea. I dive a dry suit a lot and it it behaves a bit like that.
Luis

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luis
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Re: Consider a New (Maybe Better) Direction

Fri Dec 13, 2013 1:43 pm

Here is a picture of the normal gear I use in the Caribbean. You can see the BC bladder, but I don’t even know is there. A horse collar is far more intrusive, cumbersome, and clumsy. I dove with a horse collar for decades… never again. This feels a lot more minimalistic than a horse collar or any other flotation device I can come up with.

The weight pocket on the tank band is to compensate for an aluminum tank.


Image


Note: when someone ask me which is my favorite tank my answer always is a rental aluminum 80 in the Caribbean :D
Luis

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SurfLung
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Re: Consider a New (Maybe Better) Direction

Fri Dec 13, 2013 1:52 pm

Mistralopitheque wrote:... allowing them to dive at any depth without any BCD: Weight baskets at 30ft, taking up stones from the bottom...etc. Nothing you saw on screen, but it was there. Something that is not always practical to implement in the kind of diving we do)
- Thanks for that dose of reality. Like a lot of stuff I do lately... Somebody has already dealt with it extensively in the past. At Fortune Pond, we call them "Safety Rocks" and "Drop Weights"! :D
- Consider the Sperm Whale. It's dive suit is non compressible body tissue (blubber) but it fills it's lungs with a high volume of compressible air. Supposedly the "Sperm" it is named for refers to a large cavity of a paraffin like substance in it's head that regulates buoyancy. How? That I don't know.
- In our MN lakes, the fish have air bladders for regulating buoyancy... If you pull them up from too deep, the bladder actually expands so much it pops out their mouth.
- The designer of the fish and whale went with two different systems. Both seem to work fine. So, there's hope for more than one way to do it... :roll: But, is it really worth the effort when most divers are happy with the BCD system... And, the BCD system is the one that eventually WON... Over all the other ideas that were tried.
- It is still a fascinating topic to me... If I had a suit made of blubber like the whale, I might have it licked... No smart alec comments about my blubber! :roll:
SurfLung
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Nemrod
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Re: Consider a New (Maybe Better) Direction

Sun Dec 22, 2013 2:25 pm

luis wrote:Here is a picture of the normal gear I use in the Caribbean. You can see the BC bladder, but I don’t even know is there. A horse collar is far more intrusive, cumbersome, and clumsy. I dove with a horse collar for decades… never again. This feels a lot more minimalistic than a horse collar or any other flotation device I can come up with.

Note: when someone ask me which is my favorite tank my answer always is a rental aluminum 80 in the Caribbean :D
Dittos on the aluminum 80 in the Caribbean. Though, I now own two aluminum Catalina 63s. I love them. I can generally out last most of my buddies and solo the 63s take me as long as I usually want to go in moderate depths.

Steel 72s can be problematic in Florida, thus the aluminum 63s.

Horsecollars, yeah, same here. I do occasionally use my faux USD Seatec horsecollar. And when I do I am reminded of why I went to a back inflate (wing/bp) in 1976. I just cannot abide anything pushing on my cheat. It is a phobia I have and I do not like it. If anything can make me panic, pushing on my chest is it (and red wasps or bald faced hornets in my cockpit) :shock: .

A horse collar can semi-work decent as long as it is essentially kept empty and used for surface resting. At the 2012 SD it came in handy, glad I had it, since a rip carried me quite aways from my intended submersion point. Had I been without a BC it could have been fun since I exhausted myself swimming, which is not easy to do. Yeah, I was glad I had it.

My other issue with the horse collar is that when used with the military type harness the sternum and waist quick release loops cannot be reached. This has caused me several issues, enough to swear off that combination of equipment.

And, sorry, this is the modern gear forum with double hose, so, I do not have to pretend I like the military harness. I love them for the look, I love to play with them in places like Silver Springs or Alexander Spring and I love having them in my collection but I find them less than dandy for real diving in the ocean and is why I went to the Snugpack in about 1968ish. Why?, well, several reasons, most notably is my phobia over anything touching my chest---I do not, NOT, NOT, abide sternum straps, vintage or otherwise :!: Anything with a sternum strap is not a move forward for me but a retrograde slide into a rediscovery of why my gear choices has evolved into what it is today.

I am into function first. The stuff has to work, that is my primary requirement and it all must function together.

I do have this problem, GAS (Gear Acquisition Syndrome), it works against my Minimalism :mrgreen: . I keep cruising the vdh webstore and buying stuff and then my buds at Scubatoys for what I cannot get at vdh. I think I need two clear out some stuff so I can get more stuff :roll: . I feel an Ebay adventure coming on.

Nem, the obstinate one

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SurfLung
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Re: Consider a New (Maybe Better) Direction

Mon Jan 06, 2014 12:43 pm

- Regarding the vintage harnesses with sternum and crotch straps... I noticed a serious difference between the ones made of cotton and the newer nylon versions. I use an Allan Klauda reproduction cotton harness and it seems to tighten, loosen, and release reliably. But the nylon version that came on my Twin 38s actually scared me... I was afraid the quick release wouldn't release and the sternum strap might tighten instead of loosen or release. For now, I set up the nylon harness with modern quick detach fasteners just to feel safe with it.
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