We are new owners of a 1996 C400. It has the Westerbeke 42 engine. The owners' manual seems to indicate that the engine seacock be closed everytime you turn the engine off and reopened before you start the engine. Is this accurate? Or do you just close it when you're not planning on starting the engine again for a few days, but leave it open if you plan on using it at least somewhat on a daily basis (e.g., to charge the batteries.) We ask this because it's not the simplest thing to access and if it were closed and we had to start the engine quickly, this would be a real issue.Thanks for your input!