Additional significant variable... transducer cone angle. Narrow cone = greater depth display accuracy/image detail. Wide angle = less depth accuracy, less detail, BUT more image content (water covered). Example: with narrow cone, peak of hook depth is ~accurate, while with a wide transducer cone angle, the peak of the hook may in fact be that of a target in the outer reach of the cone, displaying it deeper then the actual depth. Interpretation of display info is a multi-variable challenge