My DIY motorized Transducer Pole designs mostly focus on trolling motor mounting brackets but that only works if you have an Ultrex, Ghost or Force.
When I built the first one, I had a Minn Kota MAXXUM trolling motor so had to mount the transducer pole on the deck. I happened to run across a picture of the mount I built at the time and thought it might be of interest to others.

The base is made from an HPDE cutting board. I attached a 1 1/4 PVC Pipe sleeve to the base with conduit straps and installed a spring loaded shot pin on top of it. There is a hole in the 1 inch PVC handle extension corresponding to the stowed position and another for the deployed position. The shot pins slips into these holes to hold the pole in the desired position.