"For extraordinary heroism and distinguished service in the line of his profession as Leading Signalman of the HMNZS KIWI, during an engagement with a Japanese submarine at Kamimbo, near Guadalcanal, on 29 and 30 January 1943. Although mortally wounded and gallantly disregarding his own serious condition, Leading Signalman Buchanan remained at his battle station, skillfully training the searchlight and illuminating the target for the guns of his ship. Dauntlessly performing his task, while the corvette attacked with depth charges, forcing the Japanese submarine to the surface and ramming it, Leading Signalman Buchanan, by his intrepid devotion to duty, aided materially in the destruction of the enemy vessel."
Posthumously awarded