Boat leaking..... Somewhere

[DanielC]

I got a hole in the bottom of my muffler, (1997 Ski Nautique 2290 hours ), and I repaired it with marine epoxy and fiberglass cloth from Tap Plastics. 314 resin, 102 hardener. That was two or three years ago, still holding.

http://www.tapplastics.com/shop/product.php?pid=27&

I also had to split my muffler in two pieces to reattach an internal baffle. There is a band of fiberglass that goes around the muffler, grind it off, and the two muffler halves split easily.
When you put the muffler halves back together, lay a sheet of polyethylene plastic in the bilge, where the muffler sits, and use short pieces of fiberglass cloth to tack the two pieces together in good alignment, and a good fit in the bottom of the hull. Then remove the muffler, and seal up the joint, and any holes you find.

[DanielC]

A little more info on my muffler leak. It really did not leak when the boat was sitting, engine off, or with the engine running.
But if I shut the engine off, the muffler would fill with water, because it is below the waterline. When I started the boat, the exhaust, trying to push the water out of the muffler, would open up a crack in the muffler temporarily, and that would force water into the bilge.
In order to find this leak, I had to have the boat floating, with the engine cover, and rear floorboard removed, and start the boat. Each time I would start the boat, a big surge of water would squirt out from under the muffler.

I believe the muffler in a SANTE is above the waterline, but it may not be if you run a lot of ballast. There is also a possibility of a leak in the hull to deck joint, at the transom, if you run a lot of ballast.