I just got a hold of Citizen's technical support asking them if there are
any altitude limitation on their Skyhawk watches (they are 100WR); their
response was:
---
There are no altitude limitations. You would
not need to pull out the crown during ascent.
---


Andrey


The Visitor wrote:
Come to think of it, I have had a watch (not a cheap one) to FL230, and
there were no problems. But it wasn't a rapid decompression. In fact
I'll bet there are lots of guys up over 20,000, zooming around breathing
oxygen.

I suppose if one wanted, you could unscrew the stem on you dive watch
and it could breath, but I wouldn't bother.

John





Brian wrote:

Andrey Serbinenko wrote:

A question to the group. When I was going through my high-altitude
physiological training, they instructed us to remove wrist watches
before going for the baro-flight to FL250 (unpressurized). Has
anyone experienced any anomalies with wrist watches at low pressure?
I just can't think of why they'd require that. Even diver's watches
will hold the pressure up to a point and then the seals will leak
-- before any damage to the body of the watch or the crystal occurs.
Does the battery have any air inside that will blow it up?


Andrey


I have had the crystal on my digital watch pop out while flying my
glider up to about 18,000 feet. True the watch was a few years old and
I just replaced it with the same kind.

Brian C.
CFIIG/ASEL