Shot on infrared video cam at 9.20pm local time from a US Customs & Border Protection aircraft. Not picked up by their onboard radar.
The object was between three to five feet in length and its speed varied between approximately 40 mph to 120 mph. Its median speed was roughly 80 mph & distance travelled in the video approx 4 miles.
There was very limited interaction with the water visible in the infrared video when the object impacted the ocean. Its speed immediately prior to impact was 109.7 mph +/- 11mph.
It was picked up by the control tower of the airport as it was lit when first seen which subsequently went out, but unidentified by them.
It approached Puerto Rico out of the North from the ocean, exact origin unknown, traversed the airport then headed out to sea again.
It appears to change direction whilst underwater.
No type of propulsion is evident from the thermal imaging cam.