This video may be from 2017, however, it’s no less relevant today.
In the video well-known Rolex collector, journalist, and secondary reseller, James Dowling explains the unique characteristics of Rolex testing and manufacturing, such as how each watch is individually tested in an underground facility 4-stories tall. Before the watch enters, it’s photographed, and then 24-hours later it’s photographed again, and if there’s any divergence in accuracy — the watch is removed.
Dowling goes on to explain how the water-resistance testing of Deep Sea is done inside a machine custom-built by Comex, that’s essentially a diving bell.
There are even more Rolex tidbits you’ve likely never heard about if you watch the entire video.
Video and screengrab by Watches of Switzerland.