For conspicuous gallantry and intrepidity at the risk of his life above and beyond the call of duty while participating in a daring operation against enemy forces. PO Thornton, as Assistant U.S. Navy Advisor, along with a U.S. Navy lieutenant serving as Senior Advisor, accompanied a 3-man Vietnamese Navy SEAL patrol on an intelligence gathering and prisoner capture operation against an enemy-occupied naval river base. Launched from a Vietnamese Navy junk in a rubber boat, the patrol reached land and was continuing on foot toward its objective when it suddenly came under heavy fire from a numerically superior force. The patrol called in naval gunfire support and then engaged the enemy in a fierce firefight, accounting for many enemy casualties before moving back to the waterline to prevent encirclement. Upon learning that the Senior Advisor had been hit by enemy fire and was was believed to be dead, PO Thornton returned through a hail of fire to the lieutenant's last position; quickly disposed of 2 enemy soldiers about to overrun the position, and succeeded in removing the seriously wounded and unconscious Senior Naval Advisor to the water's edge. He then inflated the lieutenant's lifejacket and towed him seaward for approximately 2 hours until picked up by support craft. By his extraordinary courage and perseverance, PO Thornton was directly responsible for saving the life of his superior officer and enabling the safe extraction of all patrol members, thereby upholding the highest traditions of the U.S. Naval Service.