Meniscus Profiling of Fishing Lures by Optical Diffraction

Fly-fishing is a method of fishing in calm waters by attracting predatory fish with light-weight lures or "flies" that mimic insects floating on the water surface. Fly lures have long been tied by hand, using fur, feathers, and wire. Our question is how accurately fly lures replicate the physical cues of real insects at the water surface. We characterize the meniscus shape around 3D-printed cylinders and various commercial fly lures to calculate their safety factor of flotation. We show that the weighted hook mimics the insects body, wires the insect legs and feathers their wings. This work may be useful in understanding prey recognition in aquatic predators.