Army - Vietnam Combat Aviation Veteran Recon - Hunter Killer with Vietnam Service Ribbons MugHunter killer Groups, also known as Convoy Support Groups, were groups of anti submarine warships that were actively deployed to attack submarines during World War II. The advances in signals intelligence such as High frequency direction finding, in cryptological intelligence such as Ultra, and in detection technologies such as radar and sonar ASDIC enabled the Allied navies to form flotillas designed actively to hunt down submarines and sink them.