That cam lock is very cool and very ingenious.
IIRC, the Italian Navy's frogmen during WWII and just before needed a water resistant watch for their operations (which never went below 100m). Panerai, at the time, didn't make any watches, they just assembled them, so they asked Rolex for water resistant cases and they would make and assemble the rest of the components. This was the first iteration of what would become the Radiomir line (because it used radium for illumination). It was very well sealed but didn't use a screw down crown and wasn't automatic; as a result, it didn't take long for the seals inside the watch to need replacement. As this was mostly during war time, no money was going to be spent by the Italian gov't to make a better watch (and, I think, Rolex still held the patent on the double and triple lock screw down crown). After the war, to remedy the problem, Panerai invented that cam lock which really ensured the tightness of the seals and later made the movement automatic. That cam lock is now a Panerai signature.