Fire officials responded to the west basin cove side of the harbor around 9:35 a.m. The fire was swiftly put out and all of the boaters were accounted for.
One person was assessed by firefighter-paramedics and declined to be transported to the hospital.
A total of eight boats were burned with three of them destroyed. There were no loss estimates immediately available.
Orange County Fire Authority posted a video shared by a witness on Twitter, who reported an explosion.
Fire investigators determined the cause of the fire to be accidental but did not elaborate on their findings.