Better radars?

"In addition, the Japanese have provided military tracking hardware to the fleet, according to Sea Shepherd. “Essentially, they can see exactly where we are, but we still only have a rough idea of their position,” said Watson."

A reasonable guess would be spread spectrum radios for communication; they have lower narrow band spectral power output and they are harder to intercept the content of the transmissions, i.e. to determine what their plans are.