underwater sound weapon

The Navy has been granted the patent for a cavitation weapon. The powerful weapon would use sonar to generate "acoustic remote cavitation," that would destroy everything from torpedoes to mines. As the patent describes:

A method is disclosed of generating a predetermined field of cavitation around a remote target in an underwater environment. The method includes the steps of identifying a remote target location, generating at least two acoustic beams, each at a high power output, from an underwater acoustic source, and controlling the generated acoustic beams to intersect with each other at the remote target location and thereby create a destructive cavitation field at the intersection of the beams. The acoustic source and target can be located in unconfined underwater space and at a distance of at least 100 m apart.

The underlying physics is based on the intense heat and high-pressure pulse from the sonar sources 12, 14, and 16 as the damage mechanisms by virtue of the intense acoustic power of the sonar sources. An ensuing cavitation bubble formation and collapse and shock propagation will also inflict damages on underwater objects 18 targeted for removal. The technical drivers are the cavitation lethality on the undesirable objects 18 and the acoustic power of the sonar sources versus range and depth.