Catalina 18 transducer placement

[MarkHejtmanek]

I am adding a GPS/depth finder to my 2000 Catalina 18 and am struggling with where to put the transducer. The model I'm looking at has a transom-mounted version which is supposed to be more reliable/detailed than "In-Hull", and supposedly easiest of the three types to install, however, I don't think I have room in the center of the transom below the water line (rudder in center, outboard engine on port side, and swim ladder on the starboard side). I could conceivably put it outside the rudder arc on the port side as long as it's clear of the engine - realizing that the water disturbance might affect readings until I can get under sail and raise the engine).

My 2nd option is In-Hull, but I'm trying to figure out the best placement and how to get access to the inside of the hull. It looks like I might be able to cut a hole in the sole just forward of where the porta-pottie sits, or perhaps even below the V-berth where there is smooth water and it's ahead of the keel. I understand I'll lose a little detail, but I really just need it for depth soundings (that's the most critical piece of all this due to where I'm sailing).

I have not 100% ruled out Through-Hull, but it would be an absolute last resort as I'm not keen on punching a hole in the bottom of the boat.

I'd be grateful for any insight/advice from Cat 18 owners on how and where they placed their transducer.

Thanks all!

Mark

 

[sail sfbay]

This should get you started:

In general, depth transducers should be mounted in an area where the water is not turbulent. This would eliminate most areas along the keel/centerboard, off the transom and behind the keel/centerboard. That leaves the area in front of the keel. It should be mounted as close to the centerline and pointing directly down.

Consider an in hull transducer. No thru hole is necessary and you may get a better position. The depth transducer needs to point directly down (or as close as possible). This is a sample of one, it may not be the one you actually need, but you'll get the idea. Airmar makes most of the transducers on the market. AIRMAR. Information on in-hull mounting: Mounting an In-Hull Transducer on a Boat | Boating Mag.

 

[MarkHejtmanek]

Thanks - that information is similar to all the research I've done so far. I also have a call in to Catalina directly to try to get some advice. Once I find and mount the transducer, I'll report back here on how it worked. Perhaps that will help others.