My lifelong friend Bill Gallo showed me this fly on a recent trip to visit and fish the waters around his home in Key Largo. It mimics the shape and size of a ballyhoo or needle fish, both of which are so prevalent in The Keys.
The retrieve technique is somewhat unique. You hold the rod between your knees and strip with both hands to create the image of rapidly fleeing prey. This will usually elicit a response strike from the barracuda, which can be a challenge to respond to in this compromised position.