Taking on Water

26 - 27 March 2018

So we're still learning some things about our boat. We were already aware that the drainage for the shower and sink was below the waterline, making that through hull valve of primary importance. Well on Monday Heather cleaned the forward head, which pretty much involves taking a shower yourself. The water collects at the bottom and you push a little rubberized button to engage the shower sump pump. The pump was draining even more slowly than usual. After a while we got tired and left it with a little water below the grate, and a new addition for our to-do list in the morning.

When we returned a few hours later in the dark there were several inches of water in the shower. Heather was brave enough to taste it - salty! We were taking on water, albeit slowly. Taking on water is the slower, more controlled version of sinking. It certainly sounds better, and appearances matter. The sump pump was still doing a pretty pathetic job, and when we gave up a second time there was still an inch or so of water left. We closed the shower through hull valve (this time), and went to bed.

In the morning the shower drain hose was still firmly double clamped to the through hull. No leaks there. I pulled a little portable peristaltic pump I use for moving water from various places and drained the rest of the shower water into the sink and overboard. This works because while the sink connects to the same through hull as the shower, the sink itself is above the waterline, and gravity still works.

In doing some research I learned that the shower uses a diaphragm pump. If any little thing gets between the diaphragm and the seal, like say hair, then the pump will be slowed if not disabled. Like what happens in any shower drain. As a result, there is a little filter upstream of the pump. Yup, there it is. I remove the housing which includes the little stainless steel mesh screen, and boy is that nasty. Probably should have been cleaning that over the last couple years. Connected it all back up and the pump works better than it ever has (or at least since we got the boat).

So there's one last part of having debris between the diaphragm and the seal. After you turn off the pump the line is still full of water, continuously, from the outside of the boat to the last dregs in the shower sump. Ever drain a waterbed? The shower sump is below the waterline, so it is a lower place than the water outside the boat. Hmmm. All that is keeping the water you just removed, and a whole lot more, from siphoning back into the boat is that little rubber diaphragm and its seal. New boat rule, the shower through hull valve shall remain closed at all times unless in use.

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