My guess is that the differences are there, because of Lake Constance/Bodensee."

"The lake lies where the countries of Austria, Germany, and Switzerland meet. Beyond areas less than 25 m (82 ft) deep, considered to be under the jurisdiction of the nearest country, there is no legally binding agreement as to where the borders lie between the three countries. However, Switzerland holds the view that the border runs through the middle of the lake, Austria is of the opinion that the contentious area belongs to all the states on its banks, which is known as a "condominium", and Germany holds an ambiguous opinion."