OOC:
Right, my bad - thought I'd been clearer. The barge was moving downriver from Tamalir to Dawnsmoor (East to West).
As for scale on the map the developers rather unhelpfully decided not to include one. One post they made on the FAQ forum is that at it's widest point Terrinoth is roughly 250 leagues which they say is approximately 900 miles.....I work that out to be closer to 750 miles based on UK Leagues which I'll be using. So after taking that into account I'm gonna say the distance between Dawnsmoor and the southern tip of the lake (rough area where Ethanath thinks the goblin settlement is) is about 50 miles, assuming that you're not pushing too hard it'll probably take 3 days overland without mounts.
I've updated the map - red cross is roughly where the barge was attacked and the red circle is the area that was indicated as most likely for the goblins.
Hope that helps clarify things some, let me know if you want anything else