Back Sonoboje German Ηχοσημαντήρας Greek Sonoboya Spanish Sonopoi Estonian Bouée acoustique French Sonoboia Galician Sonoboya ID Sonoboa Italian ソノブイ Japanese 소노부이 Korean
A sonobuoy (a portmanteau of sonar and buoy) is a small expendable sonar buoy dropped from aircraft or ships for anti-submarine warfare or underwater acoustic research. Sonobuoys are typically around 13 cm (5 in) in diameter and 91 cm (3 ft) long. When floating on the water, sonobuoys have both a radio transmitter above the surface and hydrophone sensors underwater.