Portable fish finders won’t require any physical installation, just software calibrations and adjustments.
For mounted/fixed units, at least the transducer must be mounted on the boat, and the process will depend on the mount type:
Transom mount: the transducer is mounted at the transom, at the rear of the boat just below water.
Through-hull mount: you will need to drill a hole in your hull—if necessary—to screw the transducer to your boat’s hull. The transducer is permanently placed inside the hull of the boat.
In-hull mount: the easiest to install, as we simply place the transducer anywhere inside the ship, pointing to the hull.