Replace head thru-hull fittings
DISCUSSION:
Observed outside, the hull material around the two thru-hulls for the head appear to need re-glassing. In addition, the head output (effluent) thru-hull was leaking inside the hull in 2007.
Note that the head's raw-water input thru-hull is shared with the sink's output water.
Photo 1 below shows the relative locations of the two thru-hulls on port underwater.
The upper right thru-hull is the head output (effluent) thruhull, while the lower left one is the head's raw-water input thru-hull.
Photo 2 below shows the output thruhull as viewed from a bit aft.
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Above, we've chosen to show the gap between the flange of the thruhull and the hull. We don't know whether this is the place that is leaking.
Photo 3 below shows the same output thruhull, but from a little bit forward. An experienced eye is needed to opine whether the glass is separating in the inside of the flange.
Photo 4 below shows the other thruhull, i.e., the head raw-water-input thruhull.
We don't know of any leaking by this thruhull. However, the hull surface appears to have been patched bery badly, and an experienced eye should determine whether this surface is dangerous.