Water Resistance without Crown Gasket

Hey Everyone,

I recently assembled a GMT watch with a water resistance rating of 20 ATM, or 200m. The caseback has a gasket, but there is no gasket for the screw down crown so I’m worried about taking this into any kind of water. Most watches I’ve seen with a screw down crown and a water resistance rating of 200m or more have a gasket protecting the crown.

Does anyone have any light they can shed on this? Anybody have experience with their GMT’s in water for a swim, etc?

Also, does anyone know if a gasket can be added to the crown to improve water resistance?



My dive watch, which I assume has the same construction as the GMT watch, fares well in water.

I guess if the watch isn’t built with a gasket in mind, it’s pointless to add a gasket to it. It wouldn’t have the groove for the gasket to stay in place.