Shantha was born to K. G. Gunathilaka and R. M. Dollienona, and resided in Norwood, Hatton. He was married at the time of his death, to R. M. S. R. Dissanayake.
On the dawn of 1 November 2008 at approximately 5.45 am, a battle erupted between the navy and a group of Sea Tiger boats off the coast between Point Pedro and Nagar Kovil, near the northern tip of Sri Lanka. At the time, Shantha was a Petty Officer in the navy's elite Special Boat Squadron. He was in command of the Arrow-class patrol boatZ-142, which was armed with a 23 mmautocannon and two machine guns, and was part of the navy group engaged in the battle. Shantha and his crew engaged the Sea Tiger vessels, using the high maneuverability of the Z-142 to their advantage. However, all three gunners were eventually incapacitated, and Shantha was left unable to attack the enemy boats now approaching the navy's larger vessels. A Sea Tiger suicide boat was heading towards the P-164, a Colombo-Classfast attack craft of the 4th Fast Attack Flotilla carrying 10 sailors. Seeing this, Shantha maneuvered the Z-142 into the path of the suicide boat and rammed it. He was killed in the resulting explosion which obliterated the suicide boat and the Z-142 with it, but the P-164 and its crew were spared. The outcome of the battle is unclear, as both sides claimed victory. The Sea Tigers claimed that they had sunk two navy vessels and forced them to retreat, while the navy claimed that they successfully repelled the attack and destroyed at least four Sea Tiger vessels with the assistance of the air force.
Recognition
Shantha was promoted posthumously to the rank of Chief Petty Officer. On 16 December 2011, a house was donated to his family, which was constructed by the Naval Engineering Division with funding from First LadyShiranthi Rajapaksa. He was recommended for the Parama Weera Vibhushanaya, the country's highest military award for gallantry, for his actions on 1 November 2008. The decision to award the medal to Shantha and 14 others was announced in The Sri Lanka Gazette on 16 May 2012. It was presented to his next-of-kin three days later on 19 May 2012 by Mahinda Rajapaksa, the President of Sri Lanka, at a ceremony held at the celebrations marking the third anniversary of the end of the war. The citation for Shantha's Parama Weera Vibhushanaya commends him as a "bold sailor commanded his craft in the midst of danger, using his instinct and wisdom, encouraging his fellow sailors, disregarding the risk to own life and security, with the objective of safeguarding thereby the lives of his comrades." Shantha was the second recipient of the Parama Weera Vibhushanaya from the navy, after Lieutenant CommanderJude Wijethunge who received it posthumously for similar actions in 1996.
