From the Executive Summary of an extensive report based on an investigation of this sighting by the Scientific Coalition of Ufology (SCU):
On April 25, 2013, at about 9:20 pm local time, an unknown object at low altitude flew directly across Rafael Hernandez airport runway at Aguadilla, Puerto Rico, causing a delayed departure of a commercial aircraft. There was no squawking transponder signal to alert the aircraft tower, nor was there any communication with the tower to prevent a dangerous situation with departing and arriving aircraft. Fortunately an airborne US Customs and Boarder Protection aircraft captured the object on infrared video.
An original copy of a thermal video was obtained from an official source on October 10th of 2013. The source of this video evidence was vetted and identified. The source wishes to remain completely anonymous to ensure no issues arise with the source's employers. The individual's occupation, address, and background history were verified by the authors of this report as legitimate. The three-minute video detailed the flight of an unknown object that crossed into northwestern Puerto Rico from the Atlantic Ocean, traversed the Rafael Hernandez airport two times, and returned into the Atlantic Ocean where it appeared to receptively submerge.