After graduation, Griffiths was posted to the
Royal Navy for further training and joined the battle cruiser . He survived the
sinking of the Repulse by Japanese air attack on 10 December 1941. He served on several ships later in the Second World War. He was promoted to lieutenant in 1944 and awarded the
Distinguished Service Cross in May 1945 "For gallantry, skill and devotion to duty while serving in in the successful assault operations in the
Lingayen Gulf, Luzon Island." Griffiths saw service as Gunnery Officer on in the Korean War and commanded the guided missile destroyer in the Vietnam War. As commander of , he assisted in relief operations in
Darwin after
Cyclone Tracy hit in 1974. In 1976 he was promoted to
rear admiral and appointed Chief of Naval Personnel. In January 1979 he took up his final posting as the Flag Officer Naval Support Command. He retired in 1980. ==Later career==