Question 42Electricity & Electronics - 1st Asst/Chief

The correct answer is A) transitioning from a stone/rock seabed to a sand seabed. When transitioning from a hard, rocky seabed to a softer, sandy seabed, the echo sounder will receive weaker returns from the seafloor. To compensate for this, the operator would need to increase the unit gain to amplify the weaker signals and provide a clearer display. The other answer choices describe transitions where the seafloor material either stays the same (C and D) or becomes softer (B), which would not require an increase in gain to maintain a clear echo sounder display.