#18 Should radar sonar?

[Markus Armbruster]

`sonar' lists detected ships and visualizes them on a map.
`lookout' lists detected ships.
`radar' visualizes them.

However: `radar' automatically uses sonar! When
#682577 is fixed, `radar' is no longer a mere
visualization of `lookout', because `radar' then risks
detection by passive sonar.

I propose that `radar' does not use sonar.

I would like `radar' to list detected ships like sonar
does, but that may break some smart clients.