During his tour there, he earned an Associate of Arts degree from Skagit Valley College and was the recipient of the President's Honor Medal (second highest GPA in the graduating class).

During a subsequent tour of sea duty as a support maintenance technician at Underwater Demolition Team 21 in Little Creek, Virginia, he was advanced to Chief Petty Officer and qualified as a naval parachutist.

While assigned to a shore tour at Naval and Marine Corps Reserve Center in Louisville, Kentucky, he was advanced to senior chief petty officer.

In September 1980, Hagan reported aboard USS Richmond K. Turner (CG-20), homeported in Charleston, South Carolina.

While there, he qualified as an Enlisted Surface Warfare Specialist and was advanced to master chief petty officer.

John continues leading his Chiefs through his active riding and mentoring role in the Old Dogs Veteran's Motorcycle Association.