Inside the boat there needs to be a valve to open or shut off the flow of water from each thru hull. This is the old inline valve for the galley drain. There is supposed to be a ball Inside the valve that rotates when the handle is turned–either allowing water to flow or blocking flow. The ball inside this valve had completely dissolved and there was no way to shut off water flow. Notice the single hose clamp and the red, plastic fitting… Code requires double clamping so that the failure of a $3 clamp won’t sink the boat. But this fitting was too short to take a second clamp and the entire setup was too frail to work on while in the water.