Ferries to Åland
Three daily connections Norrtälje-Mariehamn are mentioned in the "by boat" section. By what company are these? The article only links to Baltic Sea ferries, which is overkill for this, without useful information.
Eckerölinjen indeed has two-three daily ferries, but these are on the Grisslehamn-Eckerö route (also Åland-Norrtälje, though). The connection is very cheap: adults 5€, accompanying children under 12 years for free, car 10€.
I there some confusion or are these latter connections simply missing? The "by boat" section was copied from Kapellskär, and so Grisslehamn connections missing is natural. This, and connecting buses, should also be added to Eckerö.