🔍 Key Concepts

• Depth sounder range setting controls how deep the screen looks below the transducer • Depth sounder gain setting controls how strong/visible the echo returns appear on the display • If the true depth is greater than the selected range, the bottom trace will be off the screen, not just faint

💭 Think About

• Ask yourself: if the seabed became deeper than the maximum value shown on the right-hand range scale, where would the bottom trace go on the display? • How would the picture look different if the gain were simply set too low – would the entire screen be empty, or would you still see some weak returns or noise? • Look at the illustration’s right-hand scale and the range knob: which control would bring the bottom back into view if it has gone off the edge of the screen rather than just faded?

✅ Before You Answer

• Check the range scale numbers on the right side of the display against the known or expected charted depth in the area. • Consider whether the screen shows any background noise or surface echoes – if you see some noise but no bottom, that suggests a range issue more than gain. • Verify which control (range vs. gain) actually moves the visible depth window deeper or shallower on this specific model, as shown in the illustration.