Ball valves (in-line valve or flanged seacocks) that are "exercised" frequently operate more easily and are likely to remain free of marine growth. The task of regularly opening and closing valves, however, is often neglected because valves are difficult to reach, or because owners just don't feel like it. Consequently, valves are left in one position for months or even seasons, and when the time comes to open or close the valve, the build-up of barnacles and calcium makes it extremely difficult or impossible.