From sightings by U.S. submarines to mysterious humanoids in the depths of Russian lakes, there is an even more mysterious cousin to the UFO - the USO, or Unidentified Submerged Object.

From sightings by U.S. submarines to mysterious humanoids in the depths of Russian lakes, there is an even more mysterious cousin to the UFO - the USO, or Unidentified Submerged Object.

There are multiple reports of USOs from around the world, often from respected military and academic professionals - with some claiming that underwater ‘fast movers’ are a common part of life on board submarines.

Speaking to DailyMail.com, Nigel Watson, author of Captured by Aliens? A History and Analysis of American Abduction Claims, said: ‘We live on an ocean planet, so it is not surprising that UFOs are seen over or in the vicinity of the great expanses of water that surround us.

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