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. [cascade flags: wikipedia_dropped_other_sources_exist | tier=unverified indep_score=0.3 clusters=3 claim_tier=notable] [rescored 2026-09-15: curated origin-host map (PR #65); unclassified hosts no longer scored as aggregators]
Sources
- Baltic Sea anomaly (wikipedia)
- https://www.marineinsight.com/maritime-history/the-baltic-sea-mystery-of-the-strange-ufo-object/ (corroboration)
- https://esovitae.com/the-baltic-sea-anomaly/ (corroboration)
- https://www.thisunexplaineduniverse.com/articles/baltic-sea-anomaly (corroboration)