....and what's on MSN this wednesday evening, dazzlenation?...towed array sonar, anybody?....go figure:

RAF fighter jets scrambled to intercept four 'Russian bombers' approaching UK (msn.com)

Russian submarine hit Royal Navy warship sonar in North Atlantic - BBC News

Dazzlenation (tumblr.com)

along with something that mcdonald might be interested in:

18 Passive and active SONAR for submarine detection. Passive: the... | Download Scientific Diagram (researchgate.net)

(PDF) Classification of Surface Vehicle Propeller Cavitation Noise Using Spectrogram Processing in Combination with Convolution Neural Network (researchgate.net)