A marine seismic source in which capacitor plates are highly charged and then allowed to discharge via a transducer in the water. Eddy currents induced in the transducer plates force the plates apart, thus producing a low-pressure region between the plates. Water implodes into this region, generating a pressure wave. The Boomer (the name is a commercial trademark) is used in high-frequency marine surveys as a low-energy (less than 1 kJ), high-resolution seismic source. The term ‘boomer’ is also used colloquially to describe a high-amplitude, low-frequency reflection event associated with a large and distinctive reflector.