IOC started with a regional programme in the Western Pacific in 1965. The first project involved the Kuroshio current which flows from the tropical Pacific northward via the East China Sea towards the North Western Pacific. Twelve countries in the region participated and supported the joint research project. 

Other projects followed. In 1977, a Regional Committee for the Western Pacific was established during the 10th IOC Assembly in Paris. Since 1979 regular sessions of the committee were held, coordinated by the IOC Headquarters in Paris. Initially emphasis of the tasks of the committee was on fundamental research but its programme subsequently evolved in line with IOC's main thrusts. 

In 1989 the Regional Committee for the Western Pacific was tranformed into the IOC Sub-Commission for the Western Pacific (WESTPAC). Its main task was to develop, co-ordinate and implement regional marine scientific research programmes, ocean observations and services, data and information management and capacity building, all these in the context of priority interests of the Member States in the region.