Well I went to Sports Authority and bought a $10 fishing shirt that has several pockets and is a cool materal that dries fast but I also carry a camelbak for things not needed at most caches like ziplocks, camo tape and other things for repair as well as my raincoat and off course 100 oz of water. In the shirt I carry my Palm, GPS, Sig coins and spare battries as well as other things that swap in and out as I see fit like camera and mardi gras beads, it is also vented in the back. I had a photographer's vest but decided it was too hot even though it was made out of a net matterial.