Check your thru hulls

Just a reminder for us northern guys whose boats are still out of the water, check your thru hulls! Last September we purchased our “new to us” 2013 370. The boat was traded in so we purchased from a well known local dealer. In addition to the dealers inspection I had the boat independently surveyed as well. Turns out they both missed a boat sinking sized problem. The mushroom end of the thru hull for the speed log transducer was completely sheared away, sans a fingernail sized piece. There was no real mechanical connection left to the hull and it was held in by sealant alone, had this broken free, 2 inch hole in the bottom of the keel. Just a small amount or pressure with the hull nut removed and it fell right out of the boat. The sealant on the broken transducer was wet and discolored indicating that it had been this way for some time. I have to assume that the boat was lifted via straps at the wrong point, cracking the fitting, or that it was over tightened when installed and the pressure broke the end off.

Replacement airmar transducer housing installed with 4200 and the other transducer was re-bedded while I was down there. Crisis averted! Just hard to imagine that had that not been caught and broken free while underway that it very likely would have sunk the boat.

Thanks for sharing and glad you caught it.

Through hulls should be inspected every year for wear. Those above the water line degrade from u/v exposure. The equally important issue is the bedding around them that may be letting water into the balsa coring in the hull. Many manufacturers do a less than optimal sealing job when building boats. If you have elevated moisture readings around fittings, they need to come out and the hull dried out and repaired before installing new through hulls. Painting through hulls with Imron or Awlgrip will prevent future u/v damage. Bronze fittings, properly installed are the best, but are not in common use in production boats.

I had an old transducer let go underway. Bilge pump was comming on regularly. Stopped, took a look, pulled what remained of the tranducer and a whole lot of water came in. Did my "oh chit," put the thru hull back in the hole and made a bee line for the hoist to get the boat pulled. I carry those wodden plugs just in case.