Position-finding device (5)
I believe the answer is:
sonar
(Other definitions for sonar that I've seen before include "echo device" , "Underwater detection system" , "Detection system at sea" , "location device" , "Underwater echo sounder" .)
I believe the answer is:
sonar
(Other definitions for sonar that I've seen before include "echo device" , "Underwater detection system" , "Detection system at sea" , "location device" , "Underwater echo sounder" .)