What plane does the transducer acquire it's images. Just the bottom, the bottom and sides, some of the top as well?
Bottom and sides with any Side Imaging (SI) transducer.
A well mount will work, but ensure the side of the 'ducer
have a clear "view" to either side. It must be low enough
in the water so that the bottom of the boat isn't in the way.
The Down Imaging (DI) feature will probably still work
if the sides beams are blocked.
The well-mount is a good approach for trolling motor
application. You have easy access to deploy the 'ducer
once you've launched so it won't hit bottom. Otherwise,
swapping the mirage and the 'ducer is impractical while
Then again, you could just mount the 'ducer to the
trolling motor so long as the motor is fixed and
doesn't turn (rudder is used to steer). The 'ducer
can't rotate while SI is used.
Another option would be the thru hull...
The DI feature will probably work, but SI definitetly
won't work thru-hull. I advise buying a less expensive
DI-only model for a dedicated thru-hull mount.
...what would a wall look like?
I've seen trees, roads and bridges, sunken boats,
brush piles, etc but never a wall. It takes a while
to learn how to interpret what you see. But once
you learn the basics, it's not hard.
Search for "humminbird SI" at YouTube . Visit sites
which target your specific type of fishing. For example,
I visit "crappie.com" and they talk about using SI for
panfish. There are sites for saltwater, stripers, walleye,
etc and they all discuss how to use SI for each species.
These two sites are also good resources...Humminbird Side Imaging ForumsUnofficial Humminbird Side Image Forums