Years of UV exposure weakened two of these three plastic drain fittings. The outboard flanges dropped off and the hoses fell Within the boat, leaving prospective boat-sinking holes just above the waterline. Doug Logan Photograph. A USCG certified captain and previous merchant mariner, Peter d'Anjou has become a freelance author https://forboat.eu/marine-plumbing-supplies-for-boat/thru-hull-fittings-for-boat/