BC Innovation

[halocline]

While YOU and I and MANY on this board prefer a backplate and wings, the OVERWHELMING majority of recreational divers, EVEN WHEN PRESENTED with both solutions, still choose the standard buoyancy jackets, with all of the gadgets.

Phil Ellis

And just where are these divers when making this decision? Inside a dive shop, or, as Perrone helpfully added, on a website. This is exactly my point.

Another thing is that the choice involved doesn't have to be between the bloated jackets and a BP/W. The old zeagle scout was heading in the right direction; no cumberbund, very simple harness, sensibly small aircell, no ditchable weight system. And, in fact, Scott Zeagle used to say this was his favorite warm water BC, and of course he could dive any of his own products. But they dropped it, too bad.

 

[Thalassamania]

I kind of figured those were the different styles of ballast tanks, but can you expand on just taking pressure reading? Are you talking just ambient pressure, as in depth?

Various ROVs and submersibles have had "Stay Here!" Some operated on pressure alone, some on pressure and compass reading and some even on pressure, compass and short baseline telemetry.

My intention is not to maintain a constant depth, but to compensate for known buoyancy changes. I don’t want the system to fight the buoyancy I intentionally generate with my lungs.

I was thinking in term of constant depth, but if you design the circuit to update as a function of depth (often at shallow depths and less frequently deeper and to attempt to adjust to the current depth rather than to some previous value, would you not wind up with the same effect, but be independent of the type of suit, etc.?

Actually, can you point me to somewhere for more info on the different ballast tanks/ systems?
Just curiosity, I am no where near to start building or designing. I have too many other smaller projects in front of me.

I know that this is just a fun design exercise ... I can't really think of any textbooks on the subject, most of the Navy stuff tend to be classified. John Pritzlaff and I did a paper for the IEEE that touched on these topics, when I unpack I'll see if I can find a copy for you.

 

[redrover]

BUOYANCY COMPENSATION: USE OR ABUSE. (1976) Lee H. Somers, Ph. D.

The link doesn't work.

 

[redrover]

I think BCs need more tweaking about as much as a hair comb does. How about divers learning basic buoyancy control? It's not that hard to learn and a lot more reliable than a computer driven device that adjusts buoyancy.

I can see innovations although they may not be what you are meaning by innovation.
One is; I’ve got 2 recently designed or ‘new’ jacket BC’s, both I like and dislike equally. Each has features I wish were on one or the other.
I’ve looked at the limited options locally and considered many more, from the barest BP/W thru to jackets and each is missing one or more feature I desire, or at least I think so. An industry innovation would be one of everything, every size available, for live testing at a nominal shipping fee. Very few rental test dive options are available to me.

 

[CODMAN]

Ya know all, they used to use diving bells to go under water. Then all of a sudden someone though:" There must be a better way of doing this. Here, lets try this innovation..."... And diving gear and procedures have now progressed to where they are. It's called evolution and for it to work, you need to try new things to see what works (good ideas as well as bad ideas).

I'm sure there are much better ways of designing dive gear that we just haven't figured out yet due to our lack of knowledge. If we listen exclusively to those who don't want things to change, we'll never get better. Personally, I don't think staying stagnant is very interesting... So please don't try to hold back the inovative people of this world! Just dive, and let dive, no matter if you swear by a BP/W or a BC.

By the way, this can be applied to many aspects of life...

Just my 0.02$ on this (and I'm not going to add in any more, since I already know where this post is headed...)

 

[PhilEllis]

And just where are these divers when making this decision? Inside a dive shop, or, as Perrone helpfully added, on a website. This is exactly my point.

Another thing is that the choice involved doesn't have to be between the bloated jackets and a BP/W. The old zeagle scout was heading in the right direction; no cumberbund, very simple harness, sensibly small aircell, no ditchable weight system. And, in fact, Scott Zeagle used to say this was his favorite warm water BC, and of course he could dive any of his own products. But they dropped it, too bad.

I think I see your point. There is a reason why traditional dive stores stock mostly what the people are buying.........because that is what the people are buying.

In my store, we show back inflated jackets, standard jackets, soft pack technical harnesses, and back plates and wings. We explain the benefits and advantages, along with the disadvantages of each. All that aside, standard jacket style buoyancy systems out sell all others in my store. It is no different in other parts of the country. It is not completely a mistake that you don't see YOUR choice of buoyancy in most stores.

Phil Ellis

 

[DiveNav]

John Pritzlaff and I did a paper for the IEEE that touched on these topics, when I unpack I'll see if I can find a copy for you.

I will be interested to see your paper too :blinking:

Best Regards

I_AM

 

[Thalassamania]

The link doesn't work.

Try:

http://www.oseh.umich.edu/diving%20articles/buoycomp.pdf

As a Charter Member of the "Michigan Mafia" I have to direct you to a great set of papers:

Occupational Safety and Environmental Health

Click on the "Articles of Interest" tab

 

[bpstordy]

There are three physical approaches, flexable bladders that take on and dump gas (what we call "soft" buoyancy in the submersible biz), rigid containers that use gas pressure to move water out (hard buoyancy) and rigid containers that use a cylinder with a piston that is moved by a worm gear to control the amount of water in the tube. There's no need for the control circuit to look at suit compression or tank contents, just pressure. "Stay Here!" means (with appropriate buffering) keep the first derivative with respect to pressure at zero.

It also had a huge amount of drag.

Hi there Thalassamania,
I know that this thread has been dead for 6 years, however I was wondering whether I could get your input on the topic of automation in buoyancy control. I'm an engineering student at the University of Toronto and for an project in my engineering design course my group and I have come upon the idea of developing a device to improve the experience of Scuba divers and more specifically the notion of creating a device to at least partially automate the process of buoyancy control. The project is still in its earliest stages, and as such I was hoping that I could get in contact with you in order to understand whether a project in this vein is worth pursuing as well as any other input you may have, seeing as you appear to have a lot of experience with both scuba diving and automated buoyancy control. If you'd be willing to chat about this further please feel free to either contact me here on this forum, or email me at ben.stordy@mail.utoronto.ca

Regards,
Ben Stordy