The Zürichsee-Schifffahrtsgesellschaft or Lake Zürich Navigation Company (commonly abbreviated to ZSG) is a public Swiss company operating passenger ships and boats on Lake Zürich.

The company operates services connecting lake-side towns between Zürich and Rapperswil, as well as more tourist oriented cruises and boat services on the Limmat through the centre of the city of Zürich. It is a member of the Zürich Public Transport Network (ZVV) and transports over 1.5 million passengers every year.^[1]

The ZSG is a joint stock company with a share capital of 11 million Swiss Francs (CHF). The share capital – one third is in private hands – is divided into 110,000 bearer shares, each with a nominal value of CHF 100.^[2]

Steam navigation started on Lake Zürich in 1834, when Franz Carl Caspar and Johann Jakob Lämmlin founded a new company (Caspar und Lämmlin, Unternehmer der Dampfschiffahrt auf dem Zürcher- und Walensee) and ordered their first ship from William Fairbairn of Manchester, England. Minerva entered service the following year.^[3] When the cuty fortifications were abolished, the then called Bauschänzli bastion remained intact, and served from 1835 to 1883 as the landing site for the first steamboats on the lake, later provided by the Zürichsee-Schifffahrtsgesellschaft.^[4]

Over the years, various other companies started operating steam ships on the lake, and various mergers took place, until the entire fleet was taken over by the Swiss Northeastern Railway (NOB) in 1874. The NOB also owned most of the railway network around the lake, and this monopoly led to consumer resistance, and to the formation of the Zürcher Dampfbootgesellschaft (Zürich Steamship Company) in 1890/91. In order to operate a tram-like suburban traffic, a series of nine screw steamships was ordered.^[3]

When the NOB became part of the Swiss Federal Railways in 1903, the Zürcher Dampfbootgesellschaft took over its fleet of ships on Lake Zürich. This included the large paddle steamer Helvetia. In 1909 and 1914, it ordered two further large paddle steamers, which were to become today's Stadt Zürich and Stadt Rapperswil respectively. In 1934 the Zürcher Dampfbootgesellschaft introduced its first successful motor ship, the Etzel, and from then on the fleet became increasingly motorized.^[3]

For the Swiss National Exhibition of 1939 [de], four sister motor ships, the Taucherli, Schwan, Möve and Ente, were brought into service. These vessels provided a connecting service between the two exhibition sites, at Wollishofen and Zürichhorn. The Second World War brought economic difficulties, but the cross-lake services were maintained. As a consequence of the transition from steam power to motor vessels, the company changed its name to Zürichsee Schifffahrtgesellschaft, or ZSG for short, in 1957.^[3]

In 1990, the ZSG became part of the Zürcher Verkehrsverbund (ZVV), the public transport network established in the same year, accepting the ZVVs common tickets and tariffs.^[1]

In 2009 there was a centennial exhibition on board Stadt Zürich at Zürich-Bürkliplatz. On 12 June 2009, exactly 100 years after the maiden voyage of the steamship Stadt Zürich, its anniversary trip with invited guests and its sistership Stadt Rapperswil was celebrated.,^[5] and in 2014 for its then 100 years aged sistership.

The ZSG operates regular round trips from its main Zürich landing point at Bürklipatz. In summer, trips taking 4 hours operate every hour and stop on both shores of the lower lake at Zürichhorn, Wollishofen, Kilchberg-Bendlikon, Küsnacht-Heslibach, Küsnacht, Zollikon, Meilen, Herrliberg, Rüschlikon, Thalwil, Erlenbach, Oberrieden, Horgen, Au peninsula, Wädenswil, Richterswil, Stäfa, Männedorf, Ufenau island and Rapperswil. A few trips continue through the Hurden ship canal to the upper lake, or Obersee, calling at Altendorf, Lachen and Schmerikon, and take 7 hours.

There also are shorter round trips from Zürich-Bürkliplatz, with 2.5 hour trips as far as Richterswil or Stäfa, and 1.5 hour trips to Erlenbach and Thalwil.

The company also operates services on the Limmat through the centre of Zürich. These services operate upriver from the Landesmuseum via Limmatquai and Storchen to Lake Zürich, stopping at Bürkliplatz, Enge and Zürichhorn,^[13] before returning downriver to the Landesmuseum. Because of the low bridges over the Limmat in central Zurich, these services use low profile motor boats.

The ZSG employs approximatively 80 permanent members of staff, and in the main summer season (April–December) five additional nautical seasonal workers, as well as seven staff in the ticket office at Zürich Bürkliplatz. In its own ship yard at Zürich-Wollishofen work qualified carpenters, painters, mechanics, electricians, plumbers and locksmiths.^[14]

• Zürichsee-Fähre Horgen–Meilen, the main car ferry operator on Lake Zürich