evidence: Covering an area of 536 sq. km, Lake Constance, also known as Bodensee in German, is a large body of water that is shared by the three European nations of Germany, Switzerland, and Austria. The lake forms a part of the Rhine River basin and is geographically positioned at the northern foothills of the Alps. Lake Constance is considered Central Europe’s third-largest lake by surface area and also the second largest lake in Europe by water volume. Lake Constance is situated at an elevation of 395m and has a maximum length of 63km and a maximum width of 14km. The lake has an average depth of 90m and reaches a maximum depth of 251m at its deepest point. The shorelines of Lake Constance are shared by the German states of Bavaria and Baden-Württemberg; the Swiss cantons of Schaffhausen, St. Gallen, and Thurgau; and the Austrian state of Vorarlberg. [...] Lake Constance plays a major economic role for all the three European countries that share the lake. The lake serves as an important drinking water source for southwest Germany. It is estimated that more than 70 million visitors visit the lake every year. The Lake also offers many recreational activities like hiking, diving, swimming, and sailing, during summer and skiing during winter. The Romanshorn boat harbor is regarded as the largest leisure harbor on Lake Constance.