Check this vintage ad out...

[Open Ocean Diver]

Not vintage but current condition of Lauderdale by the Sea pier.

 

[Open Ocean Diver]

Scubapro 1965 catalogue, valve with an integrated gauge allowing diver to know how much air is in his take it all times. Interesting

 

[Akimbo]

Scubapro 1965 catalogue, valve with an integrated gauge allowing diver to know how much air is in his take it all times. Interesting

Interesting but not very useful. The scale was very small and the mechanism was not very reliable in salt water, which resulted in having very little practical value.

 

[Open Ocean Diver]

Interesting but not very useful. The scale was very small and the mechanism was not very reliable in salt water, which resulted in having very little practical value.

I guess you would have to remove your tank to take a peek.

 

[JMBL]

Interesting but not very useful. The scale was very small and the mechanism was not very reliable in salt water, which resulted in having very little practical value.

Still, the idea was a good one. It was redundancy in its earliest stage I guess. I know of another 'weird' contraption, which would have been quite good I think : an SPG readable front the front and above. So your buddy could read it, as well as yourself. It was fitted on an early French scuba, the "Poumon d'Eau" (i.e aqua-lung ever heard of that one ? lol), designed by Georges Herail, in the 50s, in Toulouse (S-W France, nowadays home the Airbus plane). Here's a picture (said SPG on the left).

Link to a full article about the Poumon d'eau (in French only, sorry, but I don't know of any documentation in English about this scuba)

 

[antique diver]

Relatively few of us (at least in my area) were using submersible pressure gauges in 1965, and the built-in gauge on the valve at least gave us an idea of approximate beginning pressure before the dive.

We weren't pulling the tank off occasionally for a pressure peek during the dive. Instead, we just depended somewhat on past experience of time and depth combinations, and hoping the reserve would give us ample warning.

BTW, that didn't always work out too well!

 

[Bigbella]

Relatively few of us (at least in my area) were using submersible pressure gauges in 1965, and the built-in gauge on the valve at least gave us an idea of approximate beginning pressure before the dive.

Back in the 1960s, many of the regulators didn't even feature an HP port, such as the early Poseidon Cyklon models, which only had a single LP port for a second stage.

Instead, a double reserve manifold from Aqua-Sport / Poseidon was offered which had a then-radical feature, for its time -- an HP port (seen in last photo) where a new-fangled and a quite expensive SPG, for its its time, could be added . . .

 

[Luis H]

Interesting but not very useful. The scale was very small and the mechanism was not very reliable in salt water, which resulted in having very little practical value.

I guess you would have to remove your tank to take a peek.

It was actually very useful in the dive shop to tell which tanks need filling.

I felt that it was very reliable to tell that a tank needed filling, but the opposite wasn't true. I didn't trust it as much to tell me that a cylinder was actually full. It wasn't precise enough to tell me that it was truly full. If it appeared to be full, but I wasn't sure, then I would double check with a tank checker.

 

[Open Ocean Diver]

edit: anyone recognize what she’s holding with her right hand.

 

[antique diver]

Anyone still use an navigation board?

View attachment 766587

Try moving the letters around in the last word, and this will make more sense.
BTW, the item in lower left looks more like a metal detector to me.