Featherweight, Incredibly Easy, Very Effective... Not only will this boat sonar system give you instant depth readings, from 2.5 to 199 Feet (.7 to 60.1 Meters), in 1/10th precision, but at the press of a button the display will give real time temperature (water or air) and fish readings. Use it in the winter to shoot through ice before cutting your hole. Use it in the summer as a range finder and temperature meter while diving. Use it as a backup marine depth sounder on your recreational boat or scan for channels in your dingy.