Deck : General Navigation - 879/2138
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| When using an echo sounder in deep water, it is NOT unusual to __________. |
| A) receive a first return near the surface during the day, and a strong return at about 200 fathoms (366 meters) at night |
| B) receive false echoes at a constant depth day and night |
| C) have to recalibrate every couple of days due to inaccurate readings |
| D) receive a strong return at about 200 fathoms (366 meters) during the day, and one nearer the surface at night |
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