The Baltic Sea anomaly was discovered by a team that was treasure hunting on the floor of the northern Baltic Sea.
Notes on verification
Confirmed by multiple independent, reputable sources (CNN, NBC, HowStuffWorks) all corroborating that Ocean X Team, led by Peter Lindberg, discovered the anomaly while treasure/shipwreck hunting in the northern Baltic Sea in 2011. [cascade flags: aggregator_dropped_primary_exists | tier=silver indep_score=0.7 clusters=2 claim_tier=notable]
Sources
- Baltic Sea anomaly (wikipedia)
- https://www.cnn.com/2012/01/28/world/europe/swedish-shipwreck-hunters/index.html (corroboration)
- https://www.nbcnews.com/id/wbna48844496 (corroboration)