Automatic Buoyancy Compensator

[Jim Lapenta]

And how affordable would it be? Another gear solution for a clear training problem.

 

[dumpsterDiver]

Divers have done everything you mentioned in your previous post without a BC. So it seems to me that it is technically feasible to do the same thing with an automatic BC. Also I do not see where I advocated diving without a BC.

The CO2 cartridge was an emergency device only, the BC had a normal inflator. As a matter of fact the BC is still being manufactured and sold today for the military market. Seatec-Original Military Manta

Divers CAN NOT control their bouyancy without a BC as well as they can with one. The whole premise that "back in the day" the same functionality was acheived with no BC is ridiculous. If the divers are going deep, in thick wetsuits, there is no substitute.

Except.... I forgot.. When i got my first drysuit, there were really only horse collar BC's and they were not compatible with the drysuit, so I just used the dry suit for buoyancy control and wore no BC. This was before power inflators were common on Bc's, so being able to press a button (on the dry suit) and get neutral was pretty damn cool... but i hated wearing 40 lbs of lead with my unisuit.

 

[JoshuaHeard]

Thanks for your feedback. At this point, we have not put in a manual inflation or deflation valve, so a diver will have to kick to ascend or descend, and could not rely on positive or negative buoyancy to accomplish this task, but this is something to consider. There is a manual adjustment for the diver to adjust the device to his individual buoyancy at the beginning of the dive or if the diver gains mass during the dive, for instance hunting lobsters.

I don’t know how sensitive the device will be. We have worked out the physics and are making a CAD design of the actual device. We should have a testable prototype by this summer. It should not cost more than current BCs. I will keep this forum informed on our progress.

 

[JamesK]

Hmmm. I would be interested to see how this works with a rebreather!

 

[scubafanatic]

Thanks for your feedback. At this point, we have not put in a manual inflation or deflation valve, so a diver will have to kick to ascend or descend, and could not rely on positive or negative buoyancy to accomplish this task, but this is something to consider. There is a manual adjustment for the diver to adjust the device to his individual buoyancy at the beginning of the dive or if the diver gains mass during the dive, for instance hunting lobsters.

I don’t know how sensitive the device will be. We have worked out the physics and are making a CAD design of the actual device. We should have a testable prototype by this summer. It should not cost more than current BCs. I will keep this forum informed on our progress.

Tobin (deepseasupply.com) is a valuable resource on this board for all things bouyancy control related, have you reached out to him for his insight ?

 

[BRT]

Hi Joshua,
Are you a scuba diver? Technically, I'm confident I could build a BCD that would hold a level but I would never consider using one. We tend to go up and down within a small range a lot on purpose. I certainly don't want any device trying to stop me from doing that. And if it isn't capable of holding within a small range it certainly won't hold a safety stop. And the last thing I want is something using my air without my control.

 

[elan]

My understanding from the title that he is building a compenstor that will maintain neutral buoyancy - not that will maintain specific level. If the device can measure its own volume precisely enough it is fairly easy to calculate how much needs to be added to maintain its own buoyancy at certain level. Its even possible to calculate wetsuit buoyancy changes up to some point. It could be very tough to do when there is another big airspace invilved (drysuit for example) and having newtral buoyancy does not mean that the object does not change the depth. That will only be true when there are no other forces involved and that is not possible in the wild. For example a neutrally buoyant object that is thrown into the water will be sinking down until the water resistance will not slow it down. Than it will stop at certain depth. If it gets another impulse it will move again until water resistance does not stop it.

 

[BRT]

My understanding from the title that he is building a compenstor that will maintain neutral buoyancy - not that will maintain specific level. If the device can measure its own volume precisely enough it is fairly easy to calculate how much needs to be added to maintain its own buoyancy at certain level. Its even possible to calculate wetsuit buoyancy changes up to some point. It could be very tough to do when there is another big airspace invilved (drysuit for example) and having newtral buoyancy does not mean that the object does not change the depth. That will only be true when there are no other forces involved and that is not possible in the wild. For example a neutrally buoyant object that is thrown into the water will be sinking down until the water resistance will not slow it down. Than it will stop at certain depth. If it gets another impulse it will move again until water resistance does not stop it.

That will be some computer that can calculate the compression on everybodies wetsuit!

 

[Progen]

So many negative posts when nobody has even seen or tested the device yet. And it's not like as if he's asking for funding to build it. If it doesn't work, it'll make a good bed for his cat if he has one. If it does, a lot of people are going to be eating humble pie.

ps. I'd best not mention about my idea for a device to control your buddy's buoyancy!








pps. That was a joke!

 

[KeithG]

Thanks for your replies. This automatic BC is fairly simple and would be an advancement on current BCs. It basically uses the change in water pressure to increase or decrease a volume, which allows a diver to automatically maintain neutral buoyancy throughout the dive at any depth. With current BCs a diver must manually adjust the volume in the BC in order to maintain neutral buoyancy. This is, at worst, potentially dangerous for new divers, and, at best, a distraction for advanced divers. A device that automatically maintains neutral buoyancy for a diver would remove the chore of manually monitoring and changing the air volume in a BC and would allow the diver to concentrate more on the enjoyment of the diving experience. It would also be safer and more efficient than current technology.

I believe you need to think this through a little more. In order to provide a mechanism that will maintain a divers neutral buoyancy, you need to be able to measure whether a diver is positively or negatively buoyant.

Simply sensing changes in water pressure will not accomplish that. Measuring changes in water pressure will only indicate if the diver is ascending or descending or maintaining depth. It has no relationship to their buoyancy. I can be positive and descend by swimming down, or be negative and ascend by swimming up.

You can create a device that will become more or less buoyant based upon changes in water pressure. And knowing the proprties of that device, you can make that device neutrally buoyant. but this will have no relationship to the divers buoyancy. It may either over or under compensate.

For this concept to work you need to be able to measure in real time the positive or negative mass of the diver and gear. This is relatively easy to do, as long as the diver is not ascending or descending (suspend the diver via a rigid beam and measure the expansion or compression on the beam - otherwise known as a load cell).

Or you could create a device that attempts to maintain it's current depth. Not sure any one would buy one of those.

Cheers...