[C320-list] Through-Hulls

[David Veeneman]

I am taking inventory of the through-hulls on the Catalina 320 I bought a few months ago, and I’ve come across a couple of items that puzzle me. I have a through-hull that I can’t identify, and a Y-valve that I don’t understand.

In my aft cabin, on the starboard side of the cabin, I have two access doors, a large one and a small one. Both provide access to through-hulls with seacocks. The small door accesses three through-hulls. Two are labelled as the head inlet and the shower sump outlet. The third is unlabelled. Can anyone tell me what this third through-hull is? Here’s a picture of the layout:



It’s the front through-hull that’s unlabelled.

The large access door opens to a y-valve that appears to connect to the head outlet. A hand-drawn diagram on the bulkhead indicates that one y-valve setting directs directs the output to the holding tank (the current setting), and that a second setting is ‘off’. But the other hose from the y-valve leads to a through-hull with a seacock (which is closed). Here’s a picture of the y-valve:




The y-valve looks like its handle has broken off, so it looks like I’m going to have to replace the valve.

I understand the current y-valve setting—the head evacuates to the holding tank, which I can either pump out (which is what I do), or I can run its contents through the macerator and dump them in the ocean (which I haven’t done). I don’t understand the y-valve, which seems to give me the additional option of simply dumping the head directly into the ocean.

I can’t see any reason why I would use the y-valve setting that evacuates head output directly to the ocean. Is there a reason I would want to do that? Any light that you can shed on this issue would be greatly appreciated.

Thanks for your help.

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David Veeneman
Dana Point, CA
SV Adelante, C320 #131