 Large scale whaling began in the 1957–58 season, when the Slava fleet penetrated the waters off Australia for the first time, killing 2,200 humpbacks alone during this season.In 1958–59, the fleet killed more than 4,000, and did not report most of its catch.As the limit on humpbacks at the time was only 1,250 per season (or a limit of only four days to hunt humpbacks) the whalers needed to conceal most of their catch to avoid ramifications during the annual meetings of the IWC.