No, but there are disadvantages to long bills, and that is why you rarely see experienced fly-fishermen wearing them. While you may not realize it, as your line is unrolling on the forward cast you visually monitor its flight. No doubt on many casts you instinctively realize it will overshoot the target and make adjustments as necessary. When wearing a long-billed hat, you often don't see the line until it's too late. The other disadvantage of the long bill is that it is so easily swept off your head by a heavy wind.