Automatic Buoyancy Compensator

[tridacna]

I doubt that anything will change the inventor's mind. The issue is whether such a device has any potential of gaining a toehold in the market.

I believe that it won't for the following reasons:

1. If it ain't broke, don't fix it. Achieving neutral bouyancy with a BCD is not that hard. Sure it takes some practice but all divers get it eventually. Or at least some version of it. Yes, some remain overweighted living in fear of not being able to make a safety stop but most get it and using your breath to control your bouyancy is kinda fun anyway..

2. This is a solution to a problem that does not exist. Buying a cumbersome complex piece of equipment to replace your BCD requires a really good reason to so. I would never change my BPW. It's so minimalistic and comfortable. Jut why do I need this thing? What does it do for me that my BCD/BPW does not do already?

3. Beginners and "once-year" divers will want it. Baloney. Beginners will continue to be trained in BCDs and will rent them like they usually do from their LDS and resorts. Very few ops are going to invest in these things. Agencies will not change their standards and instructions to include a more complex and expensive device.

4. It's been tried before. There are many patents and devices out there that claim to do exactly what the OP wants to achieve with this. None have been a commercial success. Nor have any gained any traction.

5. Attracting investor dollars. Almost impossible. Create a prototype. Then make it look reasonable and test it. Big bucks. And not from an investor. You need to show proof of concept FIRST then deliver a BP that shows big profits. Moreover this industry is not big enough to create something that will excite too many investors. Unless you can get one of the big manufacturers to partner with you and resell the doodah, you have no hope whatsoever. Think distribution. And the fact that Mares (or whoever) already has a patent and the fact that there are many others out there will deter most manufacturers and investors.

Personally, I would not spend too much money and time on this device. Now if you could perfect that O2 gel that allows divers to breathe without tanks, that's a different story...

 

[GHTZijderveld]

On the Nautilus Dacor CVS, yes it works, I have one in functioning condition and used it a number of times, bought it new, or better, my old man bought it for me in San Fransisco around 1980. It was a great fun toy at the diving club. If someone wants pictures and details I can send them. Some observations from experience, though it is a long time ago:
1. As said, you set a volume and that is maintained by the system. It does not compensate for variation in the wet suit volume, hence between 0 and 33 ft (10 m) where the suit volume doubles/halves, you get to light coming up, which can be compensated to a certain extend by trimming a bit to the negative. Remember, with a neutral BC we also handle our actual trim by our breathing. Below 33 ft the effect is significantly less and the CVS is more effective.
2. How do you set it's volume; There are two big spring actuated close valves, the bottom on can be locked open/close, the top one can be opened up manually by pushing against a grip, located close to the bottom valve, both at the right side of the body of the CVS if you wear it. On entering the water, with the thing full of air, you lock the bottom valve open and actuate the top valve, resulting in the unit filling with water until you are more or less a bit negative. (At least that's how I all did it) and lock the bottom valve, volume is fixed.
3. With the system closed and a bit negative, you descend to your planned depth, on the left top of the body, there is a hose like on a normal BC and a dedicated inflator/regulator, like a second stage with an inflator function, not unlike the air2 or similar, which opens up at a certain pressure differential, allowing air to flow into the CVS keeping the volume constant.
4. At depth, I used to retrim and continue the dive, the experience is a bit strange, you more or less are hanging below the unit. And it can be quite noise with that huge body and water/air gurgling thru it.
5. Upon ascend, I went a slight bit to the negative for reasons mentioned earlier and came up. Air would escape thru the top valve, water never was pushed out, it may have to do with air being less dens than water and more quick to move, never got that one figured, or Dacor never thought about it. I kept the valves well maintained otherwise they would pop open with pressure shots next to your left ear, not really enjoyable.
6. The set was quite integrated, the small regulator had some means of emergency breathing, though nothing like what came later, don't know what's out there now, have not dived for 10 years, just to busy. It also had a channel between the attached air tank and the body in which lead weights could slid, c/w emergency release.

Remember, in those days, late 70s, early 80s, the BC's came in and you still had the "air wings" attached to the tanks, which did not really act as life vest. So it was an open fight, and like being mentioned, with the advancement of BC, they really got hold, being also less costly than the CVS. (There was also an Italian design, saw pictures of it but never in real life) Hence the CVS was never further developed. A lot of it looked like it was a protoype.
As said. I still have the thing in A1 condition, though I would have to check up on the regulator diaphragm and valve rubber.
If anybody is interested I can post or send some pictures.

Govert Zijderveld