There are very few watches that have "clockwork" movements, Rolex are one of them
Why is that good? There aren't many laundry mangles sold these days either, and they'll see you right when the electricity goes off, too. Doesn't make them worth having.
As for survivability, the Rolex website only lists two watches, the Sea-Dweller and Submariner, which are proof to more than 100m. The Submariner makes it to 300m. The Sea-Dweller claims to do 1200m, although that's pretty much immaterial since you wouldn't be alive at that depth. My Casio was rated to 100m, although I only ever took it down to 10m (since I only do casual snorkelling). A very quick search for dive watch on Google found a quartz movement one rated to 500m for £150. You might have bought your Rolex because it was the only thing that'd do the job back then, but damn sure it ain't the case now.
Do many people wear stainless steel jewellery Graham?
Yep - check the market for piercing jewellery, for one. More usually though, low-end white metal jewellery is silver simply because it's easier to work. The more upscale Rolexes use gold (yellow or white) or titanium, and those are *certainly* jewellery metals.
"But whether they tell the time or not is completely secondary to their real purpose, which is to look pretty."
Now is that a fact Graham? Somehow doubt that very much.
Yes it is a fact, I'm afraid. Go to the source. Check out the Rolex gallery. Or the various James Bond posters. How are they presented? It sure as hell ain't as functional, workmanlike objects. Especially not the ones covered with diamonds.