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These things are used for oceanography data collection and have even crossed the Atlantic (in 221 days, no one said they were fast!). They work by adjusting their buoyancy to create forward movement but usually have a set of wings. Kind of like one of those cereal-box submarines that you had as a kid, but without the need for baking soda. Their commo is via satellite.
But the funny thing is, it took the Chinese 3 years to figure out its not theirs…or at least three years to make the statement known.
According to Chinese news sources:
When Huang Yunlai from Hainan province found a one-meter-long, torpedo-like device while fishing 3 years ago, he took photos of it and informed the province’s National Security Bureau immediately. Experts preliminarily concluded it was suspicious and brought it back for further analysis.
It is now confirmed that the unmanned underwater machine, disguised to look like a torpedo, is an intelligence device capable of taking pictures with fiber-optic and satellite communication. It was secretly placed in the water by a foreign country to obtain information on the Chinese navy fleet’s operations at sea.
Image may be NSFW.
Clik here to view.

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