He served on the Belgian Coast, first with 5 Naval Wing, then with 8 Naval Squadron from May through October 1916, and further inland for another year, through November 1917. He did not open his victory roll until 23 January 1917, after his transfer to 8 Naval, when he drove an
Albatros D.III down out of control while piloting a
Sopwith Pup. After a lapse of some months, he used a
Sopwith Triplane to score four times in April, becoming an ace on the 30th. May was an especially notable month for Booker, with nine victories, including a triple on the 24th. On 22 June, after his 17th win, he was awarded the Distinguished Service Cross; the citation noted his three wins tallied on 24 May. After three victories in July, he shot down and badly wounded German ace Hauptmann
Adolf Ritter von Tutschek, commander of Jasta 12, on 11 August 1917; Tutschek would take half a year to recover. In this same fight, Booker was so badly shot about that German ace
Viktor Schobinger claimed Booker as a victory. Booker actually managed to coax his destroyed 'Tripehound' to a forced landing in friendly territory. He had used Sopwith Triplanes (his usual aircraft being serial number N5482, which he whimsically dubbed 'Maude') to run his string of triumphs to 23 by this time. The crash landing on the 11th was the end of 'Maude'. It had been his mount for at least 14 triumphs. On 27 September, he scored his first victory while flying a
Sopwith Camel; he shot down German ace Oberleutnant
Hans Waldhausen of Jasta 37, who became a prisoner. However, Naval 8, and Booker, were withdrawn from action in November and returned to England. Booker was the fourth ranked of the 25 aces in this prestigious squadron. ==Second tour of service==