Glad to be appreciated, guys! Now, as promised, some later Barakuda snorkels. We'll begin with the 100 series. First comes 101:
German: "Ohne Ventil. Farbe: rot und blau. Best.-Nr. 3 822 00."
Rough translation: "No valve. Colour: red and blue. Order No. 3 822 00."
The caption says "No valve", which begs the question what the gadget topping the snorkel might be. My tentative conclusion is that it's probably a "splash cap" designed to keep water out when just the tip of the barrel is above the surface. Here's a different example of a snorkel with a splash cap, which I won recently on eBay. It was in pristine, unused condition, a miracle as it must be half a century old:
Here's how this snorkel appeared in the contemporary literature:
The third image above is from the 1956 E. T. Skinner (Typhoon) catalogue, which identifies the model as a "Typhoon Breathing Tube Model 'T1' - tube opening protected by splash cap. Allows the wearer to breathe underwater so long as the tip of the tube remains above the surface".
And here's how the snorkel operates in practice, this from the October 1954 issue of the British Sub-Aqua Club journal
Neptune:
The above image always puzzled me because I could see the air bubbles emerging from the top of the snorkel without understanding how they did so when the top of the snorkel appeared to be sealed by the blue rubber "splash cap". So I dismantled the snorkel, which I had recently won on eBay, to satisfy my curiosity.
Here's a close-up of the splash cap fitted to the top of the tube:
Note the holes punched on either side of the aluminium alloy tube. That's where the inhaled and exhaled air enters and exits the tube.
Here's the view inside the splash cap:
Note the "protuberance" at the bottom. That fits inside the opening at the top of the tube, serving as a watertight seal for the tube opening and an anchor for the splash cap. So the top end of the splash cap when fitted stops water from getting into the snorkel, while the loose-fitting open bottom end of the cap allows air to escape from those holes punched into the sides of the tube inside the cap.
Quite an ingenious design from the 1950s to keep water out of a snorkel. Of course, it only works properly if the snorkeller remains on or close to the surface.