They make some nice fishing shirts that can serve as a rash guard too. Any shirt will do, just the rashguard shirts dry out quicker. I am starting to see the same shirts with the hood in the fishing community. I was tempted to pick one up from Sam's Club for when I paddle the local river here.
You can get them on Amazon too, just search for Rash Guard. You can get them tight or loose. I would get one loose for running around.
Quiksilver shirts