A very long, thin, dark and moving at high speed under water, a strange object was captured by a passenger from an airplane while he was flying over the Sea of Japan to Los Angeles.
The author of this video (see below) named Jesse Akin writes that the incident took place on July 7, 2018, but his video appeared on the network only at the end of January.
The object is obviously not a submarine or a ship, it is too long for that, and its speed exceeds the speed of an aircraft. And in all likelihood it moves shallow underwater.

Some critics have written that this is just a shadow from an airplane, but the shadow from an airplane on the water usually looks very different.

On the video, more than 6 minutes long, you can clearly trace the movement of the object and how it eventually gets ahead of the plane.
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According to ufologists, a typical NGO (Unidentified Underwater Object) was filmed on the video. Such objects are usually associated with alien underwater bases.