Researchers follow the progress of a pair of 2,300-pound great whites . Betsy and Katharine were tagged off Cape Cod ' Cape Cod in this time of year . A researcher says the sharks ' tracks are surprising for August .
Researchers follow the progress of a pair of 2,300-pound great whites . Katharine and Betsy were tagged off Massachusetts ' Cape Cod in August . A researcher says the sharks ' tracks are surprising for this time of year .