Shower + Steam = Water Inside Submariner?

[jakeysrolex]

So here's a really strange story. For you, watch savvy detective minds!

I just picked up a 11661LB "Smurf"(https://www.rolexforums.com/showthread.php?t=525996) from a shop in Hong Kong that I bought from previously and have a good relationship with. Very nice condition, from 2012, all good.

Took a shower with it on the next morning.

Hot shower, ten minutes, well steamed up shower room. All still well. Went into town to run some errands.

And before we get to the next part .. I have a stainless Sub-C that goes through hell on a regular basis. Kitesurfing 3-5 times a week, meaning sand, salt water, waves, bumps and real life. Motorbike road trips all over southeast Asia. Jungles in Burma to Soi Cowboy in Bangkok, in six months this thing has been in more trouble than a lot of watches probably see, ever. And it's fine of course. Keeps time to within a second a day, all is well.

That just to put this next weird bit into some more context.

I'm somewhere on Hong Kong island. Look down to check the time on Papa Smurf. Glass looks smudged. I wipe the glass. Glass continues to looks smudged. I wipe the glass. I look closer. What in the world?

Water. Condensation under the crystal.

At this point I'm more than a little irritated. Twenty thousand plus dollars for a dive watch and a shower kills it? I'm thinking the watch maker didn't pressure test it, how long has it been like this, images of a totally screwed movement, me leaving tomorrow for another country, no time to deal with this, etc etc.

So I go back to the watch shop.

And those guys are incredible. They got me another Smurf, equally mint, already waiting for me (I messaged ahead, noting a less than well inclined Jake returning with a wet watch). They said, options, we can get your watch serviced, pick up in a few days. Or we can replace the movement. Or you can take this replacement watch, though a year older, if you want.

Love those guys. Except for this part:

They insist that it's the shower that wrecked it. Not as in "it's your fault, your problem", but almost as an aside. They tell me that it happens all the time, they always tell the Chinese (who they say love their saunas) to *not* take their watch into the steam sauna. Dive yes, sauna no.

Which, that's just stupid.

So then they go get their watchmaker to open up shop (Sunday, closed), and pressure test the watch. It passes. Perfectly, zero drop passes. They test the potential replacement Smurf. Passes as well. And this is the fancy pressure test thing with all the bells and whistles.

Weird?

And yes, the crown was locked down. I'm very careful about this. There were no impacts, I literally had the watch for less than 24 hours, and my other sub gets regular beatings four thousand times worse than a little hot shower (though to note, the other Sub never had a steamy hot shower).

So what gives? Watch tests perfectly waterproof, the shop has been around 20 years, the people telling me "no steam" have been working at the shop over ten years, and they say it like they've said it a million times.

But, steam? Really?

I don't see a warning about steam on the Rolex site, no Google search reveals his ever happening to anyone else. How's it possible that a modern Rolex sub pressure tests perfectly, a couple of hours after having been exposed to a hot shower and somehow water having gotten inside?

Anyway. A little paranoid now, even if HK and some really good watchmakers are just a flight away. Mostly curious how the physics of this work, or if there's another, better explanation.