Which of the following is NOT the correct advantage of echo-sounding?
1
A record of depth is plotted gradually and provides a periodic record of the bottom as the vessel moves forward.
2
The speed of sounding and plotting is increased.
3
The error due to estimation of water level in a choppy sea is reduced owing to the instability of the boat.
4
It is more sensitive than the lead line.
5
Question Not Attempted