Transducer CoverageThe area covered by the transmitted sound waves is determinedby the cone angle of the transducer and the water depth. The widecone angles (40°) associated with low frequencies (50 kHz) providea large coverage area for finding fish within a coverage width thatis approximately 2/3 of the water depth. However, this also meansthat wide cone angles produce less bottom detail and resolution. Asshown in the drawing on the near right, the 40° cone angle producesa coverage area of approximately a 20-foot diameter circle at a30-foot depth.The narrow cone angles (10°) associated with high frequencies(200 kHz) provide better bottom resolution and crisper detail, butcannot show a large coverage area for finding fish. The 10° coneangle provides a coverage width that is approximately 2/10 of thewater depth. As shown in the drawing on the far right, the 10° coneangle produces a coverage area of approximately a 6-foot diametercircle at a 30-foot depth.Dual frequency mode combines both frequencies to get the bestcoverage area and contour/depth readings.40° Cone Angle (50 kHz)Coveragedameter Depth10° Cone Angle (200 kHz)Coveragedameter DepthGPSMAP 276C Owner’s Manual settIng uP And usIng sonAr > understAndIng sonAr
