Playing in the rain means your grip on the disc will be compromised. Dry towels on the course are important. Putting the towels in a Ziploc not only keeps them dry, but allows the towels to be compressed in your bag so they take less space and you can carry more towels. In addition, once the towels get wet, you can put them in empty ziplocs to keep the rest of your gear dry until you get home. This saves mold and mildew from forming in your bag.