Water and Leather...
...do not mix well. Water saturation makes leather stretch. Carry a grocery bag or saddle cover with you at all times to cover your saddle if you encounter serious rain.
WaterShed doesn't mean waterproof. The top of our WaterShed saddles repel water because of a special and expensive additive in the tanning mixture. Our bottom pieces of leather however, are veg, a type of leather that has no water repellent properties. We coat the bottom of the saddles at the factory with Saddle Sauce. However, if you get the bottom of the saddle wet, there is a chance water will seep in at the edges and the leather will stretch. We do not warrant leather failure due to excessive exposure to water.
If your saddle gets wet, loosen the bolt, remove all tension from the leather and let it dry naturally.