Our Hunter was ordered with the same setup you described. Auto/manual bilge pump with a float switch in the low bilge, high water option mounted just below the floor boards. There is an alarm in the cockpit when the second float switch is activated, unfortunately the factory never added the second, larger pump or even plumbing for it so all we have is a float switch connected to an alarm horn right now. The new large pump is in my workshop waiting or me to figure out how to plumb it.