First BC in 1968?

[Akimbo]

I noticed this ad on the back inside cover of the October 1968 Skin Diver Magazine the other day. This is the first device on market I can recall that was intended as a Buoyancy Compensator rather than an emergency floatation device that could be inflated at depth like the Bouée Fenzy.



One of these is also on E-bay, thought his link won’t last forever:

1968 SCUBA EQUALIZER SAFTBALLAST DIVING SCUBA DIVER AD | eBay

Can anyone think of an earlier BC, home-brew or on the market?

 

[Eric Sedletzky]

Dacor had something similar which you flooded completely with water at the surface then when you went deep it automatically displaced the water with air keeping you perfectly neutral the entire dive automatically. From what I understand the ballast tanks were fiberglass.
Sea Rat has one I think and when I saw it and it was explained I thought it sounded pretty neat.

 

[Luis H]

That is very interesting. I have never seen one.
I wonder how many they made and if it actually worked.


I have thought about making some rigid ballast cylinders that would look similar, but my purpose and intended function is a bit different.


Thanks for sharing.

 

[Splitlip]

Pretty cool.

I never saw that one. But...think submarines (and empty tanks) BCD development certainly could have gone that way. I saw some similar in the 70's.

 

[Luis H]

Dacor had something similar which you flooded completely with water at the surface then when you went deep it automatically displaced the water with air keeping you perfectly neutral the entire dive automatically. From what I understand the ballast tanks were fiberglass.
Sea Rat has one I think and when I saw it and it was explained I thought it sounded pretty neat.

I have a Dacor Nautilus (that needs to be serviced) and have used one in the past. They are made out of hard plastic, but not fiberglass.

They will maintain a constant ration of air volume to water in the ballast tank, but in practical use that is far from perfect neutral buoyancy.
If your buoyancy changes due to suit compression or as the tank gets lighter from consuming the air, you have to manually readjust the air to water ratio, which is not as easy as in a flexible bag.

It was a neat idea ahead of its time. With todays technology a dive computer could be program to control the rigid ballast tanks to compensate for any variation of buoyancy due to wet suit compression or weight loss due to air consumption, etc. But it would cost too much and the complexity is basically a solution for a very small issue.

 

[Akimbo]

Here is a thread on developing an automatic BC that touches on some of these design issues. That is probably why I reacted to this ad.

http://www.scubaboard.com/forums/research-development/397397-patent-pending-number-________.html

 

[Sam Miller III]

I checked my catalogs found nothing in 1968, but did find a four page full color catalog/instruction sheet for Saf-T-balast in 1969, price complete $49.95.

Apparently it was introduced in 1968 and marketed in 1969.

I have seen several of them, Nic Icorn has one in his collecton.

However I never saw one on the beach in SoCal

Never had the opportunity to dive a Saf-T-balast,

SDM

 

[Eric Sedletzky]

I have a Dacor Nautilus (that needs to be serviced) and have used one in the past. They are made out of hard plastic, but not fiberglass.

They will maintain a constant ration of air volume to water in the ballast tank, but in practical use that is far from perfect neutral buoyancy.
If your buoyancy changes due to suit compression or as the tank gets lighter from consuming the air, you have to manually readjust the air to water ratio, which is not as easy as in a flexible bag.

It was a neat idea ahead of its time. With todays technology a dive computer could be program to control the rigid ballast tanks to compensate for any variation of buoyancy due to wet suit compression or weight loss due to air consumption, etc. But it would cost too much and the complexity is basically a solution for a very small issue.

Yeah, that was it the Nautilus. My mistake on the construction material I thought it was fiberglass
I can see the idea but perhaps a little convoluted.

 

[John C. Ratliff]

Here is a photo of me with the Dacor Nautilus in the Clackamas River. It is a pretty bulky unit, but functions well in the water. I have only dived it in shallow water, and so cannot say much about it diving deeper, but it seems to be a very reliable unit. I have two, one with and one without the special regulator that comes with it. That regulator is critical in keeping the pressures equalized, so if it doesn't work or is missing, that is a problem (I hooked up an old regulator to it to use, with several modifications). The Nautilus floats me high enough that my double hose regulator doesn't free flow.

However, this unit did not come out until the late 1970s; it is shown predominately in the 1978 Dacor catalog.

I have a different unit by White Stage which seems to operate on the same principal as the Scuba Equalizer, as it has a a large-diameter oral inflator and small holes in the bottom of the unit for equalization (the Nautilus was a closed system, and this is an open system). I'll see whether I can get a photo here to show you. It is much smaller than the Nautilus, and is built as a backpack. I don't know the date of that system.

John

 

[Akimbo]

How much pressure was the Dacor Nautilus rated for (internal and external)? It has been a while, but I believe they were blow molded polyethylene and since they weren’t very symmetrical (pressure vessel-wise) I can’t imagine that they would take much external pressure.