I have a 97 Chris Craft with 2 thru hull Perko drain fittings. They have a rubber flapper and drain the cockpit. I do not really like the design since if the valve inside the boat fails or hose breaks it could sink the boat. One of the housings outside broke last year and I need to replace it. Does anyone know where to get these or better yet is there a plug I could use to fill the hole and eliminate this totally.