You would still have to be able to mount it in a location that does not have any air passing under it.

Some things you can try with your present transducer besides lowering the whole transducer farther into the water:
- lower the back end of the transducer downwards so that it is angled forwards just a little bit (~ 5 degrees max.). This will help shed the aerated water around the transducer versus under it.
- try adding something as a spacer between the transducer and the hull. The idea here is to get the transducer farther away from the edge of the transom-hull and into more air bubble free water.