I love big maps, and this is no exception. Sure, it can be hard to see how coastal territories connect with all the islands and inlets, etc., but that's nature's fault, not the mapmaker's. I did see one extra connection that shouldn't be there, but I cannot remember now where it was. I think it was on the northern Baltic coast somewhere.
My only suggestion for improvement is to link Gotland to Bornholm for greater mobility.
Thank you for your feedback. Looking through the territories around the Gulf of Bothnia, I believe the superfluous connections are around Luleå in Norrbotten, Sweden, and I will have this fixed for the next version. Thank you for bringing this to my attention.
Now that you mention it, I agree that the southern Baltic could do with some more water connections. However, I think I will connect Bornholm to Öland instead, since I find Gotland to be a little bit too far.