oh, my gosh, dude. wow. look. reporter: former navy fighter pilot alex deitrich told anderson cooper about a strange object in the sky, back in november, 2004, off the coast of san diego. the tic-tac. and that s what we affectionately refer to it as because that is what he it looked like. reporter: it was about the size of an aircraft fuselage. it was white. it was sort of and it behaved in a way that we were we were surprised, unnerved. it accelerated. or almost didn t accelerate, right? it jumped from spot to spot and tumbled around in a way that was unpredictable. former navy commander was on the training mission and
what it looked like. reporter: it was about the size of an aircraft fuselage. it was white and sort of matte finish just like a tic-tac. and it behaved in a way that we were we were surprised, unnerved. it accelerated it almost didn t accelerate, right? it sort of jumped from from spot to spot and tumbled around, in a way that was unpredictable. reporter: former-navy commander, david, was on the training mission and remembers how the object, quickly, maneuvered. the ability to hover over the water and then start a vertical climb from basically zero up towards about 12,000 feet. and then, accelerate in less-than-two seconds and disappear is something i had never seen in my life. reporter: so, what was it? the government won t say, or maybe doesn t know. for decades, the pentagon s research into these close encounters has been kept under raps, along with the images and