Help identiify a SeaQuest BC please

Last night I was at my LDS for some training when a man stopped by with some late 80s gear.

To me, the most interesting bit of gear was a pair of SEAQUEST "Ventura" BCs. As we were looking them over, we noticed a dump valve pullstring that seemed to go nowhere. A quick tug and the BC suddenly inflated.

Further inspection revealed a tiny bottle of compressed air buried deep within a fold of the BC. Scary stuff!

If anyone knows any history or has experience with this BC I would be interest to hear about it.

Yes, way back when there were self inflating BCDs, many manufactuers made them.

Didn't they actually use a C02 cartridge, like you used in a pellet gun? I remember seeing one of those when I first got certified back in the mid 80's (and it looked ancient even then).

That would be a CO2 canister. It can be removed and a port plug will cap the opening.
Nothing like a big breath of CO2 at depth to make you see all the pretty colorful fish.