Question 60 CEL02 - Chief Engineer - Limited (Alt)

The Correct Answer is A **Explanation for A (Increase the range adjustment.):** If the graphic display of the ocean bottom is no longer visible on the screen of a depth sounder, it generally means that the actual depth of the water has exceeded the maximum depth currently displayed (the "range"). The depth sounder is transmitting and receiving the echo, but the echo return time corresponds to a depth greater than the current range setting. To make the bottom echo visible again, you must **increase the range adjustment** so that the maximum depth displayed on the screen is greater than the actual depth of the water. **Explanation of Incorrect Options:** * **B) Increase the gain adjustment:** Gain controls the sensitivity of the receiver. Increasing the gain makes weak echoes stronger, but if the bottom echo is completely off the displayed range, increasing the gain will not bring it onto the screen. It might strengthen echoes that are already visible (like thermoclines or fish). * **C) Decrease the gain adjustment:** Decreasing the gain would only make the display less sensitive, potentially causing weak echoes (like fish or a soft bottom) to disappear. It would not help if the bottom is missing due to an incorrect range setting. * **D) Decrease the range adjustment:** Decreasing the range adjustment would narrow the displayed depth area, making the situation worse if the bottom is already deeper than the current range. This action would only be appropriate if the bottom was visible and you wanted a more detailed view of the shallower water column.