Related Clues:

• Instrument to detect and locate distant objects
• System for detecting things using radio waves
• Underwater echo sounder
• Instrument to detect distant objects
• Detector
• Thus one hurried up to get the echo
• Thus one hurried up with the help of an echo
• The sound of a banner, perhaps, that gets the signal
• Does your boy get the artist back to help with the navigation?
• Up and down on the screen
• Fish-finding aid
• Your boy is up to painting this, by the sound of it
• 'Thus ran back, by the sound of it (5)'
• Electric eye, e.g
• Mine locator