In viewing the liquid crystal display for...

Question 1 of 2707066636eed28f7522a1c51dd61

In viewing the liquid crystal display for the illustrated depth sounder data display unit, what should be done if the graphic display of the ocean bottom is no longer visible on the screen? Illustration EL-0186

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Question 1 of 27070

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🔍 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.