I suppose that you count Porto Alegre as not "coastal" on the grounds that is on a river. I would challenge that on the grounds that the river is estuarine at that point, therefore Porto Alegre should be considered coastal.
I can see your point, the idea was exactly to make Porto Alegre a hard one to get. Instead of considering Porto Alegre coastal because of the lagoon, gonna change "coastal" for "seashore" and clarify it in the notes. Thanks for the heads-up!