A good pal , ATP , commercial, CFI, now gone west, was flying to Florida some years back in a mooney. On auto at altitude, hot sun, he was semi alert over North Carolina, his wife next to him. Suddenly she breathed in very quickly and he came alert to see U.S. MARINES suddenly in front of him. He said it was gone instantly but believes it was an F4. Said he was very alert for the rest of the trip. Wife was really shaken.