What’s the point of a Stainless-Steel watch, in the order for 20-35K€ with a mere 50 meters water resistance? When the original model, launched in 1972, without screwing down crown, could withstand 100 meters of depth, equivalent 10 ATM or 330 feet.
Although 50 meters should be enough to shower, swim (not diving) with your watch, it is not advised. I always resort to 100m of water resistance for those situations (being Rolex, with the Oyster case, one of the only brands that offer that in their whole catalog)
I will update this page with the different case constructions the RO has gone though its history, and how different seals were used and worked to protect the movement from the ingress of water and others. AP has dwelled in some really interesting articles about this matter.
A possible explanation is the aim to potentiate the Offshore collection (Bulkier bigger Royal Oak Interpretations) which, in theory, accommodate for a superior water resistance thanks to better seals. Models range up to 300 meters water resistance, which again, is nothing impressive. Rolex was achieving that many years ago with the Rolex Submariner, and at a reduced thickness…
The simpler Royal Oak Offshore sets you back a “mere” ~32.000€ while the regular Royal Oak about ~26.000€, but hey, I am sure it will help you advance on the list for any popular watch.
Page to be developed with Water Rating, graphical condiments and recommendations on water resistance (What to do, and what not to do)
https://www.watchuseek.com/threads/how-is-it-that-the-ap-royal-oak-is-a-sports-watch.5168833/