In order to unlock the Vibeke Cathrin boat, a few other boats, and this achievement, you have to travel 120 km manually. Fast travel does not count towards this achievement. It should come naturally since you have to remove the "Fog Of War" in order to locate more hotspots for fishing, and to get to other ports.
Going 120 km also unlocks the Snarset, Moby D and Svalbard boats.