Soundless flashing object crosses sky in 5 seconds, ENE to WSWThe object was intermittently flashing a bright white light.It appeared in the sky to the ENE and disappeared to the WSW in approx. five seconds.My wife thinks it was very high up; if so, its speed must have been enormous.There was no sound.It was certainly not an aircraft.The object may have had more than one light flashing.We were on board our yacht, our position about 60 miles west of Acapulco, Mexico, four miles from shore.