A thick plastic cutting board works great, cut it to the size you want. There is a fine line for transducers to be mounted correctly too low and you get rooster tails, too high and you get no readings at high speed. You want it strait up and down and skiming the surface of the water.Name: image.jpeg Views: 1201 Size: 27.5 KBA board to mount your transducer on is great as you may have to move it several times to get it just right and you won't be drilling several holes in your boat.