I always had a sneaking suspicion that I was doing something horrible to my watches by wearing them in water and now I know: almost nothing under the sun is truly waterproof. This older post by a watchmaker spells it out in plain English: most waterproof watches are, at best, not waterproof at all. Also, don’t wear your watches in the shower, for Wango Tango’s sake!
Finally – do not wear your watch in the shower. Watches are designed for cold water only. After swimming, rinse your divers watch under tap. Have the case and bracelet cleaned every 12 months. Do not expose to direct sunlight or heat. Use common sense and submerge only if you really have to. Do not be fooled by brand / model names like “promaster, diver, seamaster, shower-proof” – very often this is just another advertising gimmick.
Here is his list of absolute no-nos but read the piece for more detail:
* gold or two-tone watches
* chronograph and other complicated watches
* multi-pusher digital watches
* any vintage watches or watches over 15-20 years old
* any timepiece attached to a leather strap