The term SUBMARINE, ON SONAR can be solved by the crossword clue BLIP (4 letters). A BLIP is a short burst of sound or signal that is used to detect objects underwater. Sonar is a technology that uses sound waves to detect and locate objects underwater, such as submarines. Therefore, the term SUBMARINE, ON SONAR refers to a submarine that is detected by sonar, which is represented by the crossword clue BLIP (4 letters).