By mutual agreement of the two countries British and Norwegian pelagic whaling in the Antarctic (with which for whaling purposes South Georgian waters are included) during the season 1935–36 was limited to the period December 1, 1935, to March 15, 1936. The only factory ship not limited in her operations by this restriction was the Japanese Tonan Maru, ex Antarctic, then operating under her new flag for the second time. The pelagic season was thus limited to 106 days. In actual fact many ships ceased working before March 15; two factories had reached Norway before the end of March, and nine by the middle of April. It is hoped that the curtailment of season, and in particular the later start ensured, will have afforded useful protection to the stock, particularly that of the most valuable species, the Blue whale, which is at present the most menaced by intensive whaling.