[Frogwatch]

The old depthsounder on my 28' S2 sailboat is still good but the faceplate has become so crazed from UV as to be unreadable. I may try various ways to fix this problem but as I happen to have two identical cheap Hummingbird fish finders for my powerboat, I may simply mount one on the sailboat.
The Hummingbird transducer would be mounted on a long aluminum or stainless pole that is attached to a stanchion on the stern so it is in the water even if I heel a lot.
This would be about 8' aft of my old thru-hull transducer but it will give a depth profile instead of just a number as does the old depthsounder.
Any thoughts on if the prop flow will interfere? Pro flow on the powerboat doesn't seem to matter.
Any other concerns you can think of?

 

[ReefMagnet]

A sailboat pitches and rolls too much for a transom mount transducer. If your boat has a solid hull, you can mount the transducer in a suitable spot inside the hull on a bed of silicon or the like or in an oil bath. It may be even possible to use the existing through hull transducer from the original instrument. I've used both approaches in the past with success and, even though I currently have an overpriced instrument that just shows a number and a trend arrow, I think fishfinders are great. Not only for fishing, but for anchoring as well.

 

[marianclaire]

The original depth sounder, placed below the mast step, died about 7 years ago. The Marian Claire is a wood boat 1 1/4 " mahogany planking so no way to "see" thru the hull and I did not want to pull the mast to redo the transponder. I mounted a bottom of the line Hummingbird fish finder on the aft edge of the rudder. Rudder is hung on the stern. Worked fine until I hit 2000 RPM. Then it would not read. I moved the FF to the port side about 5 ft forward of the stern. I mounted it on a piece of UV conduit. Works great and the best thing is I can easily raise the conduit/FF out of the water when not in use so no build up of crud. It does tend to catch grass, weeds, etc if that stuff is floating around on the surface. But again just pop it up and it clears. It looks goofy and people do ask "What is that?" It does not give you any warning being positioned so far aft but I can deal with that. 10k miles with lots of exploring in shallow water and yes a few touches with the bottom but I am happy with it.
Dan S/V Marian Claire