Waterproof even for steam?

[Mike734]

Spoke to a "watchmaker" today and during the course of our conversation he talked about how people with waterproof watches like Rolex are really blowing it when they wear their watches in the shower, hot tubs or ever expose them to hot water. He says the hot/cold drys out the seals and ruins the waterproofing. He was especially cautioning about exposing the watch to steam. He says no watch can be waterproof if exposed to steam.

I don't think he is right. I'm pretty sure most any 100 ATM watch can withstand a little steam and certainly withstand showers, washing dishes etc...

What do you think? He is replacing the crystal on my cheapo Seiko. I don't think I'm going to let him near my Omega when It needs service.