Question

Explain how sonar radars work in boats

Answer 1

There is NO SUCH thing as a "sonar radar" !!!!!!

radar means RADIO, electromagnetic waves.
you send a signal pulse out and graph how long it takes (how far away) the reflections to get back in various directions

sonar means SOUND
otherwise the same idea but using sound waves, not radio waves, (in the case of a simple fathometer how long to get back from the bottom or a whale under the boat.). There is also "passive sonar" which means just listening in various directions. This gives you bearing (angle) but not distance, but has the advantage that the target does not hear your ping.

Answer 2

By the way, the reason is that radio waves have trouble propagating in the bleak ocean. Sound travels well, particularly low frequency sound. Very long (low frequency) sound waves in what is called the deep sound channel can cross the ocean. That is how the submarine Scorpion was found. Networks of transducers tracking ships by sound heard and plotted the collapse of the pressure hull.