Author, Writer, Photographer
Can you fly fish with hookless flies in closed waters?
Game Warden: What are you doing?
You: I'm fly fishing with hookless flies.
Game Warden: This river is closed to fly fishing.
You: I'm not fly fishing because my flies have no hooks in them.
Game Warden: You just admitted you were fly fishing.
You: I misspoke. I'm not fly fishing.
Game Warden: If you walk through the woods with an unloaded gun are you hunting?
Game Warden: The purpose of closing this water is to reduce the stress on fish. You may not be stressing them by playing them but you are stressing them in that they are rising to your fly but with no chance of getting any food. When no food is available, trout, especially stressed trout, will stay in a holding lie. They don't get food, but they don't burn energy. What you're doing is illegal because it stresses the fish and that is the very purpose of the closure.
In the end, it would likely end up being at the discretion of the LEO. If he writes you a ticket and you take it to court, it could end up being up to a Judge. You'd have to ask yourself, is it really worth it or could you just go somewhere that's not closed to fishing.