US Navy Sea Water Antenna System

SSC Pacific has developed a technology that uses the magnetic induction properties of sodium chloride (salt) in sea water to create a VHF antenna.

Looks very clever. It utilises the resources available.

An 80-foot-high stream could transmit and receive from 2 to 400 mHz with a relatively small footprint.

Have to assume they mean MHz. It's only a factor of a billion different.

The PopSci article that Kottke linked to seems to have just copied this. Maybe the factor of a billion doesn't bother some people.