1. An apparatus for treatment of ballast water, comprising:
(a) a generally cylindrical module having a tubular wall and an open interior along its axis;
(b) a plurality of transducer probes disposed in the wall of said module and extending more than halfway across said module,
each of said probes having a first end and a second end, the second end of one or more probes being offset from the second
end of one or more adjacent probes about the axis, said second end being located within said open interior of said module,
and each of said probes intersecting with a center of said module along said axis;
(c) a power supply for at least one of said transducer probes;
wherein said transducer probes are capable of emitting ultrasonic waves at said second end.