A graduate of Philippine Nautical School (Philippine Merchant Marine Academy), Captain Oca started as a seafarer before he became a maritime trade union leader. As founding chairperson of the Associated Marine Officers’ and Seamen’s Union of the Philippines (AMOSUP-PTGWO), he initiated programs to improve the plight of Filipino seafarers particularly in seafarer training, health, and welfare. Under his stewardship and the support of its members, AMOSUP established hospitals, housing and billeting facilities, and training centers and schools including the Maritime Academy of Asia and the Pacific. Captain Oca also worked for the protection of Filipino seafarers against proliferation of piracy in international waters and the approval of the Standard Employment Contract for mariners.
Captain Oca was a recognized leader in the shipping and maritime industry. He was Presidential Consultant on Maritime Affairs of the Office of the President from 1999 to 2001. He represented the sea-based sector in the Governing Board of the Philippine Overseas Employment Administration (POEA); the Board of Trustees of the Overseas Workers Welfare Administration (OWWA); the Board of Trustees of the National Maritime Polytechnic (NMP); and the Maritime Training Council (MTC). He was also the president of the Bagong Bayani Foundation, Inc., a private foundation that recognizes the excellence of overseas Filipino workers around the world and the Philippine Maritime Education and Training Foundation, Inc. Because of his many legacies and accomplishments, he had been awarded for his contribution to maritime trade unionism, shipping, and the Philippine society. Captain Oca was awarded the Order of Lakandula with the Rank of Bayani, the highest distinction given by the Philippine government to a civilian on June 23, 2010. He was also conferred the Papal Award Pro Ecclesia et Pontifice in recognition of his support and services to the Church on July 25, 2010.