Commodore Calunsag was born in Loay, Bohol and was married to Imelda Benavides, a Nurse by profession. He was a government scholar at the Philippine Science High School at Dilliman where he derived his secondary education. In 1970 he passed the examination for admittance to the Philippine Military Academy where he finished Bachelor of Science in Military Science. He ranked 9^th among 114 graduates. He holds Master of Science in Business Administration from the Ateneo de Manila University Graduate School of Business, and Master in National Security Administration from the National Defense College of the Philippines.

Right after his graduation from PMA, he experienced his “baptism of fire” as a young Philippine Marine Officer in the battlefields of Sulu during the campaign against the Moro Islamic Liberation Front in 1974. Shortly thereafter he joined the Philippine Navy, rising through the ranks while at the same time honing his administrative and command skills at the Philippine Navy and the Philippine Coast Guard headquarters as well as in various types of Philippine vessels. He became the first commanding officer of BRP “Apolinario Mabini” (PS-36), one of three Peacock Class offshore patrol vessels that the Philippine Navy acquired from the British Royal Navy. His achievements in his Command at Sea were highlighted exemplary achievements when he became the Naval Task Force 41 Commander. In 1983 he was in Fort Bragg, New Connecticut, USA. He attended the General Staff Course “SESKOAL CL 33” in Jakarta, Indonesia. In 2002 he went schooling in Monterey, California, USA. It is a source of pride to think that the Commanding General of the Philippine Navy is a Boholano.