Japanese oil companies have begun to set up a mutual support system to prepare for any large scale oil spillages due to the huge increase in size of tankers since 1973. In 1990, the Petroleum Association of Japan established the Oil Spill Response Department and has been conducting researches on management of oil spill combatting materials and the effective prevention of maritime oil disasters. Japan Coast Guard, in accordance with the regulations of the OPRC in 1995, formulated the national contingency plan and built a mutual-contact network among the related government institutions. Its Guard & Rescue Department. Disaster Prevention Section has been working for the maintenance of oil spill combatting materials and coordinating related work with private organizations. The Japanese government has been strengthening the maritime oil spillage management system since the Nakhodka wreck incident in 1997.