Shore power cables last for decades, but cord ends often fail sooner from internal corrosion, high amperage that occurs either from a lightning strike or low voltage at a marina, or from a short common if a charged cord end is dropped in the water. “Look for burn marks around terminals or pitting on the blades that show it’s been arcing, or any signs of corrosion” says Joe DiMaria from Hubbell. Either problem will, sooner or later, cause that cord’s connections to fail. Also check the cord end’s mating receptacle on the dock or boat, as a faulty receptacle can short a cord end, or vice-versa. Look for corrosion in and on the back of that receptacle, too, as it’s a common place for the ground connection to fail.