Adair was last seen in Bonita Springs, Florida on August 31, 2008. He went boating off Key West that day. At 2:30 p.m. he sent a text message to a family friend, saying he was going back to shore. He never arrived. He left his truck and trailer parked at the marina at John Pennekamp Coral Reef State Park in Key Largo, Florida. Hurricane Ike was passing nearby on the day of Adair's disappearance and the marina he'd launched from was evacuated.

Adair's boat, a seventeen-foot single-engine Sailfish with a center console and awning, was recovered two weeks after his disappearance, overturned in a commercial fishing area more than sixty miles west of Key Largo and ten miles south of Pine Key. The boat was in good condition and police believe it capsized in the rough weather. There was no sign of Adair at the scene.

The week before his disappearance, Adair's wife said she was filing for divorce. He took three days' vacation time from work afterwards. He was scheduled to return to his job on September 1, but did not. His coworkers reported him missing on September 2.

Adair lived on Jarrow Road in Bonita Springs, Florida at the time of his disappearance, and that city's police are investigating his case. He worked as an alarm technician. His case remains unsolved, but he is presumed to have drowned.