Sharks come in all shapes and sizes and perhaps the most unusual is the hammerhead shark, easily recognized by its oddly shaped head. Most research on hammerheads has focused specifically on their laterally expanded heads, or cephalofoil, and how they use it to see and smell as well as its effects on hydrodynamics and sensory efficiency. There are about nine known species of hammerhead sharks with dramatic differences in their body shape including the shape and size of their heads. While much is known about the variations in their electroreception, olfaction and vision, very little is known about whether or not their shape differences affect their swimming performance.