Not necessarily. During an emergency situation, one can enter a manual sound velocity.
Go to the Ocean settings; below Spreading is Sound Velocity.
To enter a manual velocity, check the box and enter the last good velocity, or take a velocity from the sound velocity profile, at the same depth as the sonar.
The SVP indicator, in the lower left portion of the GUI, will change to yellow.
As soon as possible, clear the obstruction that is blocking the probe or replace the probe.
Do not operate with a manual sound velocity for any length of time.