Where to mount external transducer on transom?

Ringer

Anybody know the best spot to mount an external transducer on a SX-166 (or similar stepped hull)? Mine's a 2000 model. Have no use for internal (thru-hull) mounting!! So I'm definitely going on the outside of the transom. Bought the 2000 SX-166 last fall, and I've never mounted a transducer on a stepped hull like this.

I don't know whether to mount it on the upper or lower step, although I'm sure the lower step will keep it in the water longer as boat speed increases. But there's not much room down there (with all the plumbing thru-hull fittings, the bilge drain, and all). It would also put the transducer closer to (or directly over) a trailer bunk board.

Upper step would be much simpler---but don't know how that might work. The transducer is for the little Humminbird dual beam Piranahmax 170.

I do know to keep it 12" or more to the right of the prop.

I'd like to be able to read depth at running speed---but it's not a must. If it's a trade-off, I'd much rather have a clear, sensitive, accurate reading at idle speed or sitting still.

JeremyL

At running speed its not going to read no matter where to put it on the transom as there will be air bubbles created, most people who have a jack plate mount it on there.