He originally flew Home Defense missions, but was reassigned to 8 Naval Squadron when it went to France.
"For conspicuous skill and gallantry during the past nine months, in particular when attached to the Royal Flying Corps, when he had numerous engagements with enemy aircraft, and certainly destroyed one.
""For ability and determination when leading offensive patrols, in which he displays entire disregard of personal danger.
"On the 1st January, 1918, he observed a new type twin-tailed two-seater enemy machine, which he attacked, firing a good many rounds at point blank range.
Compston has destroyed or driven down enemy machines completely out of control, and has frequently had more than one successful engagement in the same day."