Commander of the Sri Lanka Navy Eastern Naval Command Deputy Eastern Naval Command Deputy North Eastern Naval Command Deputy North Western Naval Command Commanding Officer, 4th Fast Attack Flotilla Squadron Command, 4th Fast Attack Flotilla
Having commissioned as a Sub-lieutenant, Sinniah went on to gain several sea commands on many vessels. Having served with the 4th Fast Attack Flotilla as a Squadron Commander and subsequently as its Commanding Officer. During the Sri Lankan Civil War he led the Naval Task Force in the destruction of LTTE arms smuggling ships over a period of two years. He has 37 LTTE hits under his command, and counts over 70 hits by the fleet during his tenure as Commander of the Fast Attack Flotilla. Vice Admiral Sinniah was the officer who apprehended the infamous LTTE ship "Kadalpura" with 19 Black Sea Tigers on board, including the LTTE second-in-command and 9 LTTE leaders, a significant milestone in the course of the war. He was the Captain of the flag ship of the Sri Lanka Navy in 2007 and served as Flag Officer Commanding Naval Fleet, The Commandant Naval and Maritime Academy, Deputy Area Commander East and The Commandant Volunteer Naval Force. He held several staff appointments in the Naval Headquarters as Personal Assistant to the Commander of the Navy; Director Naval Projects and Plans and R&D; Deputy Director Naval Administration; Staff officer Projects and Plans; Senior Staff Officer Research and Development. Served as Deputy Area Commander East North and North West Commands.[4]
Breaking with convention, President Maithripala Sirisena extended Sinniah's service period as Commander by just one month, resulting in Sinniah's retirement on his 55th birthday, on 26 October 2017. This was due to Sinniah opposing the purchase of a ship for twice its value and exposing corruption by the then government and defense secretary.[5][6]
