year, Kerry became the chairman of the Liberal Party of the Yale Political Union, and a year later he served as president of the union. Amongst his influential teachers in this period was Professor H. Bradford Westerfield, who was himself a former president of the Political Union. His involvement with the Political Union gave him an opportunity to be involved with important issues of the day, such as the civil rights movement and the New Frontier program. He also became a member of Skull and Bones Society, and traveled to Switzerland through AIESEC Yale. Under the guidance of the speaking coach and history professor Rollin G. Osterweis, Kerry won many debates against other college students from across the nation. In March 1965, as the Vietnam War escalated, he won the Ten Eyck prize as the best orator in the junior class for a speech that was critical of U.S. foreign policy. In the speech he said, "It is the spectre of Western imperialism that causes more fear among Africans and Asians than communism and thus, it is self-defeating." Kerry graduated from Yale with a bachelor of arts degree in 1966. Overall, he had lackluster grades, graduating with a cumulative average of 76 over his four years. His freshman-year average was a 71, but he improved to an 81 average for his senior year. He never received an "A" during his time at Yale; his highest grade was an 89. Military service (1966–1970) Duty on USS Gridley On February 18, 1966, Kerry enlisted in the Naval Reserve. He began his active duty military service on August 19, 1966. After completing 16 weeks of Officer Candidate School at the U.S. Naval Training Center in Newport, Rhode Island, Kerry received his officer's commission on December 16, 1966. During the 2004 election, Kerry posted his military records at his website, and permitted reporters to inspect his medical records. In 2005, Kerry released his military and medical records to the representatives of three news organizations, but has not authorized full public access to those records. During his tour on the guided missile frigate , Kerry requested duty in South Vietnam, listing as his first preference a position as the commander of a Fast Patrol Craft (PCF), also known as a "Swift boat". These boats have aluminum hulls and have little or no armor, but are heavily armed and rely on speed. "I didn't really want