What are your thoughts about our constant buoyancy BCD ?

[Akimbo]

One problem is the hydrostatic resistance appears to be constant, full or empty. Short of slogging through the patent, how does it work? I would expect to at least seeing images of your prototype on the Web site.

What is the total maximum displacement? What about using it on doubles or a single with a bailout/pony bottle?

The device uses a bladder that does not inflate at all until about 3 atm pressure. It's pressure volume characteristic is such that it changes only about 3 lb in buoyancy from 96 feet to the surface….

What if I want buoyancy on the surface before descending — on a long surface swim from the beach for example?

… Thus, it is essentially rigid with constant volume...

Is it a rigid container, as in internal and external pressure vessel? If so, what is the depth rating? If not, does a system of regulators and relief valves manage the differential pressure on the ballast tanks? If so, is it position sensitive? What is the patentable characteristic of the invention? All of the above is “prior art”, largely unpatented and used outside of the recreational Scuba market.

…You may find it interesting to look at our web site Home where the technology is explained…

Where is it explained? I saw the patent but I’m not about to dissect it.

 

[g1138]

I see a very very narrow range that this system would be useful. But diver skill can also solve those issues, which is a weakness in your system's marketing.

Tech divers and Commercial divers often use drysuits because of the long times spent in the water. Commercial divers need to have a BC that holds them upright and face out of the water. That necessitates horse collars, PFD's, or no BC: following other safety guidelines.

Tech divers won't use it because they need redundancy for system failures. Catastrophic BC punctures are unheard of. With your system, a failure can lead to complete loss of bouyancy control. Unless you have a traditional bladder with the system, I don't see how you could orally inflate enough pressure into those rigid tubes, if say your main HP hose to the system failed.

There's also the issue of drysuit undergarments often being more bouyant than a 3mm in my experience.
Hose routing this system onto a Backplate with doubles is something you'd also have to plan for.

Good point. But with changes in wetsuits and equipment, one can not always weight oneself accurately before entering the water. With this device you can make an educated guess as to how much weight you should use then add a couple of pounds. Any overweighting can be compensated for by adding a fixed volume of air to the constant buoyancy BCD.

Same with a traditional BC and a diver's intuition. So this reason is simply another method, not a solution.
And if this system doesn't compensate for above a 3mm suit then the argument is moot.


Overall, when it comes to the problem of runaway ascents, by the time you're in working dives, science dives, or tech dives, you have the capacity to deal with even minute buoyancy control while tasked loaded with what's in front of you.
Purging a BC or drysuit is second nature and doesn't take up any mind space at that level. I don't see a wide market for this in what you're suggesting as your market.

Perhaps you could patent this for a resort. Sort of like the Scuba-doo. Although that's not going to make us like it anymore (unless it keeps divers 3ft from the reef at all times), you'd possibly have a market.

 

[jadairiii]

Ask Dacor how well their constant volume "bc" worked. It was called the Nautilus CVS I believe. I am sure someone has a quick picture of it somewhere. I think Dacor's came out somewhere in the late 70's. May want to call your patent attorney.....

 

[TSandM]

It's intriguing. It would be most useful for people using either thin exposure protection or dry suits, where the buoyancy of the diver and exposure protection doesn't change through the dive. And it would be necessary to have a system for venting through the dive, as one used the gas in the tank, especially with larger tanks. It worries me a little bit that it would be even more difficult to titrate the venting with a high pressure system than it is with our current, low pressure ones, but maybe there is a way around that.

This doesn't look like it would be a good choice for people wearing thick neoprene, though, because the give and take between exposure protection lift and BC lift on those dives can be significant and repeated.

 

[Akimbo]

… Commercial divers need to have a BC that holds them upright and face out of the water. That necessitates horse collars, PFD's, or no BC: following other safety guidelines….

Considering that the vast majority of commercial diving is surface-supplied, that is inconsistent with my experience. BCs are very rarely used.

http://www.scubaboard.com/forums/commercial-divers/332573-using-bc-ssa-commercial-work.html

Also, drysuits are not very common because they are too delicate for a great deal of the work, short of heavy-gear suits that are still used in cold contaminated harbors.

 

[gfaith]

Found this one



1976 model.

A dive with the Dacor Nautilus CVS - Blogs - ScubaBoard - Scuba Diving Forum - Diving Social Network

 

[diver 85]

Is it out yet???------& if so, what's the cost???..........

 

[Akimbo]

View attachment 191249

1976 model.

Or maybe this one from 1968:

 

[raftingtigger]

For all those posters who want to know how it works - check out the OP's website and patent. Look at the pictures and you can quickly (1-2 minutes) get a sense of how it works. In short - if I understood it right - it is a system of 4 tubes that expand only after 3 ATA over ambient is reached. The volume changes only after this pressure is exceeded. Therefore once you set the volume of the system it doesn't change much over a 3 ATA range (pretty much recreational depths). I still think it is an overly complex solution to a non-problem, but very ingenious nevertheless.

I wish the OP good luck - but don't see myself ever wanting or needing such a fix.

 

[Dr. Lecter]

This is like putting complex electronic safeties on a firearm intended for self defense...too clever, too complex, too many ways for the system to fail/actively misbehave at an extremely inopportune moment.

Sometimes, simple but demanding trumps complex but idiot-proof.