"One of the main concerns is a diver coming to port and bringing explosives and other dangerous devices," Alexander Sutin, a research professor at the Stevens Institute of Technology, told AOL News in an interview. "Now we know how to detect the diver, but then how can you stop him?"
"The diver acts as an active self-disclosing acoustic beacon," according to Sutin's new paper, which lays out the concept.
Concerns about terrorist groups using swimmers or divers to attack ships or ports has been on the rise in recent years. In 2004, for example, Hamas fighters dressed in wetsuits attacked a beachfront settlement in Gaza.
The U.S. Navy, in response, has looked at ways to spot and deter swimmers and divers, using everything from trained dolphins that can spot and help capture threatening divers to airguns. Another option is acoustic devices, or "sound weapons," which work by sending out unbearable levels of sound.
Sutin's approach is unique because it's based specifically on using the diver's breath as the source and focus for the sound. The acoustic noise radiated by a diver is used to focus the acoustic energy back to the diver, without affecting the surrounding environment.
Sutin said his and his colleagues' work on time-reversal acoustics grew out of related work sponsored by the Navy and the National Institutes of Health. So far, however, he has not received any funding to work specifically on the nonlethal weapon idea.