Brad Miller discusses the versatile Gurgler Fly developed many years ago by a taxi-cab driver in New York (Jack Gartside).
This fly can be used on multiple species across the globe and used in a number of different ways.
My favorite way is to slowly slide the fly along the surface as a departure from a popper-type fly.
I suggest using the 2mm Rainy’s Cross-Linked Sheet Foam. Some people like a bit thicker, say 4mm, but the 2mm is very dense and floats very well without being too bulky.
Get it here: