DEEP SIX. The code name used by U.S. Navy Chief Petty Officer Malcolm R. Willoughby. Deep Six was born in Baltimore, Maryland, where he became known as a solitary person, spending his free time on solitaire and crossword puzzles. He eventually became a Navy diver so that "I could be alone."

When Deep Six first joined the G.I. Joe team, most Joes found him to be unfriendly and gruff, but he earned their respect for his skills. Deep Six piloted the SHARC flying submarine for the Joe team, but often he served as part of the crew of various naval vessels, including the Joes' freighter, the Jane, and the WHALE hovercraft. In his first mission on the Joe team, Deep Six served as a gunner on the WHALE hovercraft in a battle against Cobra in the Florida Everglades. He and some other Joes were injured and the WHALE was damaged in a firelight. The Joes managed to patch up the hovercraft and strike back at Cobra. The other Joes were impressed by Deep Six's will to fight on after being injured. He was hospitalized for a short time after the battle. Some time later, while serving onboard the freighter Jane, Deep Six and a handful of Joes fought off Cobra Rattler jets in the middle of a stormy sea. The Joes destroyed the Rattlers, but not before the Jane had been damaged enough to sink. Deep Six and the rest of the crew boarded a life raft and were eventually rescued.

A short time later, Deep Six attempted to destroy an underwater Cobra bunker in the Gulf of Mexico. When the SHARC's torpedoes didn't even scratch the concrete bunker, the Joes called in a bombing run that destroyed the bunker, but aggravated a fault line causing land to emerge from the ocean and form what would become Cobra Island. During a mission into the North Atlantic, Deep Six and several undercover Joes posed as the crew of a fishing boat. They were found out and fought Cobra and the October Guard while pretending to rescue a sunken American sub. That mission was fake as well, hiding their true mission to help a Soviet admiral defect to the United States. Deep Six transmitted false images of a submarine on the ocean floor using video equipment in his SHARC. The Joes managed to retrieve the Soviet admiral without firing a single shot. Years later, Deep Six would help fight the October Guard once again, transporting two Joes to Cobra Island to discover the Soviets' reason for staging a secret mission onto the island. Deep Six's subsequent missions for the Joes remain classified, but he stayed on the team until it was shut down in 1994.

Deep Six was later called back to join the reinstated Joe team in its battle against the forces of a revived Serpentor on Cobra Island. After the Joes stopped a plot by Cobra to unleash the weapon known as the Tempest, and defeated a new threat, the Red Shadows, the military again disbanded the team. One year later, the Joe team was reformed with a smaller roster of active members. Deep Six, like most former Joes, is a reserve member of the new team. He served was stationed in Algeria during the conflict known as World War III.

(GI 25, 28, 29, 30, 33, 36, 40, 49, 50; OB 1; YB 2, 4;  SM 1, 28; GIv2 24; AE 36; Figures: 1, 2, 3, 4, 5, 6, 7)