The Baltic Sea anomaly is a feature visible on an indistinct sonar image taken in June 2011.
Notes on verification
Multiple independent sources confirm the June 2011 discovery date and the indistinct/grainy nature of the sonar image, closely matching the claim.
Sources
- Baltic Sea anomaly (en.wikipedia.org)
- https://www.marineinsight.com/maritime-history/the-baltic-sea-mystery-of-the-strange-ufo-object/ (marineinsight.com)
- https://esovitae.com/the-baltic-sea-anomaly/ (esovitae.com)
- https://www.thisunexplaineduniverse.com/articles/baltic-sea-anomaly (thisunexplaineduniverse.com)