His usual watch in the early days was a Rolex 5513 Sub Mariner totally bomb proof keeps time lasts for ever, no day date mechanism known as a watch stopper a model now wanted by collectors all over the world.
I bought a Rolex Oyster Submariner in Geneva in 1973, all stainless, no day/date. Far from bomb proof. Maintenance was a headache, accuracy was questionable, but it looked good. Let my son wear it in his wedding, and that was the last time I saw it. Now he collects Rolexes. I should have known better. My current daily watch is an $18 black plastic Casio, more accurate than the Rolex, and no maintenance. When the battery dies, just buy a new watch.