sonobuoy

American  

[son-uh-boo-e, -boi] / ˈsɒn əˌbu ɛ, -ˌbɔɪ /

noun

Navigation.

1. a buoy that emits a radio signal on receiving an underwater signal from a vessel.

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sonobuoy British  

/ ˈsəʊnəˌbɔɪ /

noun

1. a buoy equipped to detect underwater noises and transmit them by radio

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Etymology

Origin of sonobuoy

First recorded in 1940–45; sono- + buoy

Example Sentences

The discovery of the sonobuoy came in the same week UK Defence Secretary John Healey confirmed the Russian vessel Yantar had been operating on the edge of UK waters.

From BBC • Nov. 23, 2025

The team initially assumed the device was part of a navigational marker, but later suspected it resembled a sonobuoy - an acoustic monitoring device, often used to detect submarines.

From BBC • Nov. 23, 2025

A sonobuoy is a combination of the words sonar and buoy and is an acoustic sensor used to detect underwater objects such as submarines.

From BBC • Nov. 23, 2025

“There’s lots of things in the ocean that will make noise and be heard on a sonobuoy, but there are few things that will sound like regular banging on metal,” he said.

From New York Times • Jun. 21, 2023

The sounds were detected by a sonobuoy, a floating device equipped with hydrophones to record noise underwater, and they seemed to be occurring at 30-minute intervals, according to a report in Rolling Stone.

From New York Times • Jun. 21, 2023