21. Through-Hull Transducers
What Happened: When hauling, the straps from the sling put pressure on the transducer, which disturbed the bedding and widened the hole.
What You Should Have Done: Properly installed transducers have large backing plates to distribute the stress of an impact. This one didn't. Or you can mount the transducer within the hull so there are no exposed parts.
What Happened: Over the years, the dissimilar metals below the waterline have been eating each other-giving them an internal structure that's similar to Swiss cheese. Eventually, a slight nudge caused one to fail.
What You Should Have Done: Again, we prefer that stainless steel or bronze be used below the waterline. But no matter what, all metals must be protected. If your bronze seacock is turning pink, it's falling apart. All underwater fittings should be bonded to each other with a number 10-gauge green wire, and sacrificial zincs should be used. Check annually.
23. Speedometer Plug
What Happened: Good move pulling the Pitot tube for a cleaning. Too bad you forgot to plug the hole.
What You Should Have Done: Vitamin E supposedly helps the memory. Even with a plug, you can get a leak. Rubber O-rings can deform or come loose from their tracks. Put some grease on the rings to ensure long life and a good seal.
24. Stern Drive Mounting Bolt
What Happened: The holes on the engine-mounting bracket below the waterline leaked due to weeping. The stainless-steel bolts inside the transom corroded due to sitting in stagnant water. This is called crevice corrosion.
What You Should Have Done: Check the drive bolts often. Double-check the seal.
25. Hose Slips Off Seacock Nipple
What Happened: After a day of wave bashing, the shakes and vibrations worked a hose off an open seacock.
What You Should Have Done: If there's room to put two hose clamps on each fitting, do it. Have the excess ring material exit in a different direction on each.