A series of 57 computer-generated maps is presented, depicting the locations of pelagic catches of Balaenopterid whales by month between 1931/32–1979/80. Two sets of maps were produced. The first series contains 24 maps of catches by species by month, and the second consists of 30 maps of catches of fin whales for each season from 1952/53–1961/62 for January, February and March, plus three summary maps of fin whales catches for the years 1952/53–1961/62 combined, for each of the three months.