Forget UFOs, alien hunters say we should be focusing on Unidentified Submerged Objects (USOs)

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.

'Concentrations of USO sightings indicate bases in the North Sea, and off the coasts of California and Puerto Rico. 

'USOs are as intriguing as UAPs but they are even more difficult to substantiate - and often get mixed with dreams about Atlantis and aliens living in the hollow Earth.

'Personally, to me, they are a myth, like mermaids or the Loch Ness Monster.'

Pilot sights ‘dark mass’ in the water

Retired Navy commander David Fravor

Retired U.S. Navy Commander David Fravor, who famously spotted the ‘Tic-Tac’ UFO in 2004, described how a fellow pilot had revealed to him an encounter with a USO.

The pilot said he had seen a ‘dark mass’, which he described as ‘big’ and ‘kinda circular’, and was not a submarine.

Fravor told the Joe Rogan podcast that the helicopter had dropped a swimmer in the water to pick up munitions.

He said: 'The first time they were out and they were going to pick up a munition, he’s sitting in the front—in the CH-53 you can see down by your feet—and as he’s looking down, they’re 50 feet above the water, he sees this kind of dark mass coming up from the depths.”

'He’s looking at this thing going, "What the hell is that?" And then it just goes back down underwater. Once they pull the kid and the munition out of the water, this object descends back into the depths.'

The pilot who was retrieving spent practice munitions out of the sea in a U.S. Navy MH-53E Sea Dragon helicopter said that a practice torpedo he was sent to recover was ‘sucked down’ into the sea by another object.

The torpedo never resurfaced.

The encounter occurred in the sea near Naval Station Roosevelt Roads, on Puerto Rico, Fravor said.

The UFOs of Guantanamo Bay

Did Marines see USOs in the late Sixties? 

In the late Sixties, ‘heavy UFO traffic’ was seen at the Guantanamo Bay base.

An ex-Marine said: ‘'All of us Marines were amazed at the amount of UFO activity over and around this base,' the witness said.

'Virtually every night UFOs were flying overhead with altitudes of less than 300 feet.’

'Most of these UFOs were approximately 50 to 100 feet across, but to the naked eye came off as a dull, hazy hull with a small red light trailing behind it,'

The marine - who wished to remain anonymous in an interview with the paranormal sighting website MUFON - said that he was unsure of the exact dates

The Marine claims he was instructed not to discuss the sightings, and said he saw one UFO which looked like a 'big beautiful cloud with a blue and white pulsating light'.

Underwater craft buzzes U.S.S. Hampton submarine

The Los Angeles-class fast attack submarine USS Hampton

A craft moving through the water faster than the speed of sound ‘whizzed by’ the submarine U.S.S. Hampton, a professor has claimed.

Professor Bob McGwier of Virginia Tech and the Institute for Defence Analyses, said the craft’s onboard sonar detected a USO moving through the water faster than the speed of sound.

McGwier was on the submarine doing classified work, and says that the crew opted not to investigate so as to focus on their mission, but did not tell him that he could not talk about the strange encounter.

In an interview with the YouTube Channel UAP Encounters, he said: 'We were underway, and, all of a sudden, I heard a sound. It is really strange and clear that something is whizzing by us.

'When I left there with the knowledge in my head, not having been told to be quiet, not having been told it was classified... It is mine to tell whoever I want. They blew it,'

The encounter with the fast-attack submarine lasted just a few seconds, McGwier says.

The underwater ‘alien base’ off Malibu

Alien-hunters spotted what many described as an ‘alien base’ 2,000 feet beneath the waves off Malibu in 2014.

When Google Earth revealed what appeared to be a ‘structure’ beneath the waves, conspiracy fans went wild.

UFO author Preston Dennett said: 'I have collected probably 50 or 100 reports of people who have seen UFOs going in and out of the water there.

‘My problem is that the Google images are coming out different, depending on what viewpoint you're looking at this thing from. Some show a tunnel. Some don't.

"I'm very intrigued by the possibility. 'm convinced there's something down there."

Geologists however have dismissed the idea that the structure is an alien base, describing the structure as ‘perfectly ordinary’.

The USOs of Lake Baikal

Lake Baikal has seen multiple bizarre sightings over the years

Lake Baikal in Siberia has been the site of multiple sightings of USOs and UFOs, beginning in the Soviet era.

Russian former Navy officer turned UFO researcher Vladimir Azhazha said, "Fifty percent of UFO encounters are connected with oceans. Fifteen more - with lakes. So, UFOs tend to stick to the water,.”

Azhazha has claimed that humanoid beings in strange shiny suits were seen in the water by military divers in 1982.

In more recent years, photographers have captured strange lights and mysterious craft over the lake.

The chairman of the Union of Photographers of Buryatia, Sergey Konechnykh, said in 2009, When I saw it, it was flying low. Until it disappeared over the horizon, I kept looking at it. I call it a fireball, and what it really was - I cannot know.'