Hauled Tanzer 27 almost two weeks ago. Water is running out from seam along leading edge of rudder below water level mark and from aft stem of rudder above water level mark. Thought I would glass the two edges and stop water from entering. However, read posts about possibility of structural failure, and some of steps required. Has anyone done this? Read about drilling holes, cutting open with circular saw, and replacing core ( foam or wood) How would I test sturctural integrity without opening up?