In 2004, US Navy pilots encountered multiple fast-moving UFOs off the coast of San Diego, California. While this story is now widely known, one detail from the USS Nimitz incident has oft been overlooked... that they also witnessed a UFO under the surface of the ocean. A UFO in the water is called a USO or Unidentified Submerged Object. And there is a very long history of UFOs being witnessed under, above or near bodies of water. From a sighting recorded by Christopher Columbus in 1492, to the Utsuro Bune folklore in Japan, or the highly-documented Shag Harbour incident, water seems to play a big role in UFO sightings.