When it comes to surf equipment, the leash is usually an afterthought. To some it’s a tangled, bothersome kook-cord, to others it’s a lifesaver. Regardless of its pros and cons, the leash is 6 feet of cord trailing behind you, and it’s essentially dead weight. Dead weight produces drag, making the leash the only piece of surf equipment not designed to improve performance on a wave. But just how much does a leash affect your surfing?
According to Aaron Perry, a yacht design engineer for ORACLE Racing (winners of the 2010 America’s Cup), every surfer feels a different amount drag. “Drag goes up with the square of the speed, so the faster you go, the higher the drag,” says Perry. “But a really rough estimate of assuming 15 mph of board-speed and a 5mm cord dragging, with 3 feet of effective length, gives you roughly 5 pounds of drag, which compared to the overall drag when paddling or riding is a small amount.”