Has anyone experienced bubbles in a compass capsule?
My backup, an older Silva baseplate Type 3 had a tiny bubble in it last week just after I returned from snowshoeing in in single-digit temps. Saturday I looked again when I was X-C skiing (again in single digits) and noticed that the bubble was much larger. It shrank and disappeared as it warmed between my hands later on. There is no sign of it at room temperature.
I suspect the fluid contracts in the cold, leaving a vacuum, or causing much smaller air bubbles to come out of solution and aggregate. If the bubble got much bigger, it could affect the needle's swing. However, since it is very light in comparison, the bubble tends to run away when the needle approaches.