I think there’s a fundamental flaw with the bilge on CS34s, or maybe it’s just ours. The lowest point in the system is underneath the kitchen sink. The previous owner flooded the bilge with antifreeze as a precaution against water getting in and freezing, causing damage.

This is another one our projects where it started simple, “let’s siphon out all the water under the sink”. And it quickly escalated to, “let’s clean the entire bilge!”.

First step was to remove all of the flooring. It all came up pretty easy. The only trick was removing the two screws at the base of the pedestal of the dining table.

It wasn’t too bad underneath, I was mostly curious to learn more about our boat.

Our friends suggested we use the following product for our bilge. It is supposed to just eat up and dissolve the scum collecting in the bilge. But I think I used it wrong.

I poured about half the bottle into the various parts of the bilge. But I found it all just ended up back under the sink. After scrubbing away at the various sections and spending a long time sponging out the liquid from under the sink (there was two 4 gallon buckets worth of liquid under there). It still didn’t look all that clean. I ended up using the stuff we use on to clean our decks and it worked much better.

In the end, I think I did finally use it right. After cleaning up and drying out all the sections of the bilge, I poured the remaining half bottle into the area with the pump. I had the pump turned off so it would just sit there, I then ran it about an hour later and it did a great job getting rid of all the scummy stuff in there.

Here’s what it looked like afterwards, not perfect, but a lot better!

An interesting part of this project was learning more about what was hidden underneath. There are these two sensors part of our Raymarine system.

The one on the left (port side) is the speed sensor. The previous owner said you can pull this out and clean the paddle wheels even when the boat is in the water. Something about a rubber tube that collapses when you pull it out. I’m not confident enough to give that a try.

I believe the one on the right (starboard side) is the depth sensor.

Lessons learned

Drain the system first. Spend the time sucking out all the water from under the sink before trying to clean anything. I didn’t and I think it diluted the bilge cleaner. I was pouring additional clean water over everything to help clean and it continually found its way back under the sink. I was using a big sponge, I think it would have been much easier to have some sort of pump with a flexible hose I could squeeze under the sink.