SONAR

Sound navigation and ranging system (5)

Solution has appeared in 2 crosswords (2 across and 0 down):

• Quick crossword No 16,300 — 2022-08-03 23:00:39
  20A: Nautical echo sounder (5)
• Quick crossword No 16,124 — 2022-01-11 00:00:01
  21A: Sound navigation and ranging system (5)