Effects of humidity on Rolex sports watches

[rollee1]

I read about a story on another Rolex forum.

A collector used 2 Submariners, 2 GMTIIs and 2 Daytonas (ss and tt), a total of 6 watches for an experiment. Duration of 1 year.
He placed the watches on winders, alternate them between indoors (normal) and placement inside a sealed electronic dehumidifier.

At over 55% humidity, the watches runs -1/+3 accuracy SCOC specs.
Both GMT & Submariner models exhibit 40-42 hours of power reserve.
Daytona runs 68 hours till full stop.

In the sealed dehumidifier electronically controlled to 55% humidity,
All models runs -1/+1, variation is between -6 +10 in 31 days.
Power reserve for GMT & Submariner extends to 50+ hours, while the Daytonas lasted 78 hours.
Repeated trials have found the watches to be extremely consistent and very stable inside the dehumidifier.

The conclusion is low humidity helps maintain stability on Rolex movements (ie healthy), he suggest to store your watches in a low humidity environment.

I thought the oyster case is sealed swim proof, interesting to discover the movements can be affected by humidity.
Regardless, I'll throw a couple of silica gel packs into my watch box from now.

[ManlyJewelry]

I don't know anything about horology, watchmaking or this supposed study done by some collector. Sounds baseless to me.

[77T]

Relative humidity is relative to the water vapor and the ambient temperature. Inside an Oyster Case the water vapor level is constant but the ambient temperature varies when the watch is in use.
Would love to see the article you reference.
My 2¢ is that accuracy on a winder or in a box is relatively unimportant to me. I need accuracy when I'm using it for days at a time on my wrist.

[Tools]

It's unlikely that humidity outside the case can affect the movement inside the case..

Temperature can definitely affect timing, as well as position (gravity). If those are not controlled precisely in all phases of the test, it is meaningless.

[GradyPhilpott]

There isn't enough to go on here to make any kind of conclusion relative to the "experiment."

However, you can't walk around with your arm in a sealed controlled environment.

I do keep my watches in a environmentally controlled environment, though, because they are kept in a safe deposit box at the bank and I do live in the high desert, so the humidity is normally quite low, sometimes in the single digits.

Your post does remind me of this, though:

[JasH]

He did not control for temperature.

[wolffram]

If we think logically, it is not possible for the external humidity level to affect the internal workings of the watch which are sealed in an environmentally isolated compartment. Temperature on the other hand, which usually has a symbiotic relationship with humidity, definitely can influence the internal environmentally sealed workings. As with all amateur experiments there are many factors which are uncontrolled and definitely have an impact on the outcome. Without seeing the test environment my money is on temperature being the primary factor at play here.