Our test group includes four units from three manufacturers. Top, from left to right: the Garmin 198C, the SI-TEX ColorMax 6, and the Lowrance 337C DF. The SI-TEX requires the addition of a converter box (lower right) for fishfinding capabilities. Below is the Garmin 178C.

Just four years ago, we paid close to $500 for the smallest standalone monochrome chartplotter on the market. Today, for a couple hundred dollars more you can have a color screen with fast screen updates, a powerful sounder, and a decent transducer all in the same compact package.

What We Tested

We limited this plotter/sounder combo test to units with color screens 6 inches or smaller (measured diagonally). Next month, we review color combos with screens from 6 to 7 inches. …