C36 Basic Maintenance 101

There isn't a sailboat owner out there-- and I mean any brand, any model -- who hasn't going through this... 

It's a gorgeous weekend, warm but not too hot, sunny, perfect winds, and some close friends or family arrived for a day or weekend sail.  The engine fires up perfectly, the sail cover's off, the jib sheets are pulled back, it's a perfect departure from the dock, and a perfect day.

So we leave the marina, hoist the sails, cut the engine, set the autopilot, and then you notice it...

As if it's it's hooked to flashing emergency lights, the knotmeter seems to scream out its  0.0 reading -- and the frustration of it is about to ruin the sail.

So what do we do?   Some of us curse Catalina, or complain about the cheap electronics.  Three truths: (1) it's not Catalina's fault, (2) we C36 owners have the factory standard in all our electronics, and (3) it's not our fault either.  It's simply a fouled knotmeter transducer, and it's just as easy to fix when sailing or motoring as it is at the dock.

Tools:

Well, none.  What's needed to fix the knotmeter is nothing more than a couple of common household/boat items.  

A small brush to scrub off the end of the transducer (TIP: a toothbrush works perfectly, although for some reason I never use my own.  Ask yourself, is your mother-in-law on board??).

And a bucket or pan and a sponge is helpful.  A big sponge is even better.

There's no reason to stop the sail or interrupt the fun.  Put someone else at the helm, take your bucket, sponge and toothrush, and go to the forward cabin.

The knotmeter tranducer is in the v-berth, under the drawers.

Remove at least the bottom two drawers (I always take all three out because I like the extra light) and stack them on the bed, the bottom one to left, middle one in the middle, and top drawer on the right).  

You're going to have to sit down, or lay down on your stomach.  

Now, see those black plastic things down there?  

I added labels to next photo to help explain...

ANOTHER OWNER TIP:  
After this chart was completed, I discovered from owner Ralph Johnson that the transducers on his C36 are reversed from my MkII, i.e. with the depth transducer to port, and the knotmeter transducer to starboard.   I realized it really doesn't matter -- they'll work the same whether to port or starboard.  Just identify the knotmeter transducer as having the twist off cap, which is there so this transducer can be removed and cleaned.  Ralph also mentioned there's an arrow on top of the knotmeter transducer that needs to be pointed forward.  Thanks, Ralph.

Okay, if this is the first time you've ever done this, I encourage you to read these next steps over once or twice before you do them. 

First, you're going to unscrew the cap on the knotmeter transducer. 

It will probably be a little bit stuck and you'll need to "jiggle" it or pull it out.  

NOTE:  When you pull it out, you've opened a hole in your boat and the sea is going to come inside.  See the next photo.  

Notice that I placed the sponge next to the transducer -- to catch water that's going to come in.

(I left the next photo larger in size so you can see the water coming in.)

Now when you remove transducer and water starts coming in, a little alarm is going to go off in your head that says something like, "OH MY GOD WHAT AM I DOING WE'RE ALL GOING TO DIE!!"  

Take a breath.  It's going to be fine.  Remember the middle "dummy plug" from a photo above?  That's coming next.

Okay, the photo is a little fuzzy.  That's probably because I was also in PANIC MODE when I pulled the transducer with my left hand and taking the picture with the camera with my right hand -- while watching the sea rush in.

Now, NOT IN PANIC MODE, take the plug, insert it in the hole you just opened up, and then screw the cap. 

There is is -- the knotmeter transducer.  At the bottom, there's a little paddle wheel.  It's kind of cool to be able to see how the knotmeter works - the movement of the boat through the water turns the wheel, which is electronically converted to determine your speed through the water.

It's a slick device -- the only problem is, things that grow in the water get on the paddle wheel and keep it from turning... 

And when it stops turning because of this growth, we have to clean it off.  

So take the toothbrush, and a little Transducer Paddle Wheel Cleaner.  

WHAT, YOU DON'T HAVE ANY KNOTMETER TRANSDUCER PADDLE WHEEL CLEANER??  

No problem.  Just use some dish detergent.

However, if you really want the specialized cleaner, send me a $300 cash and I'll send you bottle of some that will be packaged in a Joy or Dawn bottle.  :o)

It won't take long to clean this off, and the dish detergent serves not only to clean off any growth, but as a lubricant as well.  Figure maybe 10-20 seconds.  

Remember the bucket?  Hold the transducer over the pan/bucket as you scrub it, to avoid a mess.

And here's a tip from C36 owner Bill Hague for saltwater vessels:
"When the knotmeter gets fouled, remove the through hull device and soak the paddle wheel in a cup of fresh water for a few days. I do it when I'm leaving the boat and let it soak until I return to it. The 'critters' that attach themselves to the wheel die when submerged in fresh water. Everything doesn't fall of but much of it does and thereafter it is much easier to clean."

Now you'll be reversing the process:
 - Remove the plug
 - Insert the transducer
 - And screw the cap back on.  

DON'T use a huge channel lock pliers to force it on until you crack the cap in half.  That would be a BAD thing. Just hand tighten it down.  

Finally, use the sponge to clean up any remaining water under the v-berth.

And when you put the drawers back -- drawer on the left goes in the bottom, middle goes in the middle, and drawer on the right goes in top.  (The drawers looks the same size -- but they aren't interchangeable.  Keeping them in some sort of order makes replacing them easier.)