Stewart, I agree, there are some watches which we buy for their "rugged sportiness" and then don't dare wear them for anything more stressful than going to work. My Seiko Monsters are my beaters. I treat them exactly how I would a G-Shock. Surfing / Climbing / Diving / Hiking / Cycling - I've posted all the pics before - but sufficient to say, I don't baby these at all and they have never failed. Despite always wearing them on the outside of any climbing gear, they have unmarked crystals too. I think, given the other qualities ( in-house everything, solid bezel, drilled hooded lugs, world's fattest springbars, solid bracelet, Seiko history ) it is the "ultimate beater" for someone who wants a mechanical watch.
Having said all that, I'm increasingly just using my SD for everything. It's one of my 4 "never sell" watches ( the two monsters and a Speedy make up the others ) so I don't care if it picks up some signs of use.
Nice Scubapro !
Paul