radar <ship>|<sector>
   Do a radar scan from a ship or a radar station. Shows the ships you find
and a small map of what the radar sees. Range varies with ships and with
sector efficiency. Note that submarines do not show up on radar (destroyers
and submarines have sonar, however), and that PT boats are very hard to see.
Also, radar does not show ownership of sectors it displays, so beware of
relying on radar to see an enemy approaching overland. Enemy sectors will
sometimes show up as 'W', allied sectors as 'A', and everything else as '?'
if the range or weather is good enough.