That's a great question. They almost look like blocks, and one looks moved right by the wrecked ship. When was the last time the Baltic Sea was above sea level?
Possible artifacting if the surveying was done by 2 ships a certain distance from each other?
When was the last time the Baltic Sea was above sea level?
Only thing i know is that the british channel was created after thawing lakes at the end of the ice age flooded their way. Probably something similiar with the baltic sea. And before the ice age, there were no civilizations. And even before that, there was even deeper sea (before europe surfaced). So, probably never.
I agree about the wave/wrinkle looking things. I'm talking about the block looking things above the ship, and one beside it that looks like it moved from above it. I'm not sure how Lemmy works across instances but I did add a picture to my comment.