I'm not even sure how accurate the map is, though. St. Petersburg is at the eastern end of the Gulf of Finland, and it would seem that it should be in the same square as Helsinki. St. Petersburg is definitely bigger.
I guess it ends up in the same square with Moscow and thus doesn't show up but either the map doesn't show the shoreline of the sea very accurately at all or it's wrong about the location of St. Petersburg.
Helsinki has a population of 650,058 and is located at 60°10′15″N 24°56′15″E while;
Saint Petersburg has a population of 5,351,935 and is located at 59°56′15″N 30°18′31″E
Saint Petersburg is one quadrant south and one quadrant east of Helsinki, or the same quadrant as Moscow as you said.
The bay gets a little thin before Saint Petersburg, and there is a parallel passing exactly through it. I’m guessing that’s whats making Saint Petersburg appear more inline then it is, or—more accurately—makes the shoreline appear to be more to the west then it actually is.
