Baltic Sea anomaly

The Baltic Sea anomaly is a feature visible on an indistinct sonar image taken by Peter Lindberg, Dennis Åberg and their Swedish OceanX diving team while treasure hunting on the floor of the northern Baltic Sea at the center of the Gulf of Bothnia in June 2011. The team suggested their sonar image showed an object with unusual features of seemingly non-natural origin, prompting speculation published in tabloid newspapers that the object was a sunken UFO.

A consensus of experts and scientists say that the image most likely shows a natural geological formation.^{[1][2][3][4][5]}