South Harbour (, ) is a bay and harbour area immediately next to the centre of the city of Helsinki, Finland. 4.7 million passengers in liner traffic and some 37 000 international cruise passengers travel through it every year. Also over million tonnes of unitized cargo passes through the South Harbour. Most of the harbour's traffic is to Stockholm, Sweden and Tallinn, Estonia, and cruises. In summertime, there is also much small ship traffic. During the winter time, excess snow from snow removal may be disposed of in the harbor. As of 2020, the Carmel, an old vessel, was keeping the harbor open by circling 400 times within 24 hours. Geography The bay is bordered by the districts of Katajanokka, Kaartinkaupunki, Ullanlinna and Kaivopuisto. The waterway leading to the South Harbour is 9.6 metres deep. The most critical point on the waterway is the Kustaanmiekka strait, with a width of 80 metres. The waterway has a speed limit of 30 km/h, except for the Katajanokka area, which has a speed limit of 10 km/h. Piers and terminals The South Harbour has eight named piers and three terminals. The Katajanokka Quay (, ) runs nearly the whole length of Katajanokka, with a length of 740 metres and water depth of 8.8 metres. The furthest part of the pier, towards the sea, consists of the cruising ship pier, with a water depth of 10.3 metres. At the middle of the pier is the Katajanokka Terminal, used by the Viking Line cruiseferries among others. At the end near the Helsinki Market Square was the Kanava Terminal (, ), used by express ships travelling to Tallinn. The terminal was pulled down in 2012. In front of the Presidential Palace is the Linnanallas (Slottsbassängen) bay, used by visiting small boats. Between the bay and the sea lies Linnanlaituri (Slottskajen), used for traffic to Korkeasaari and Porvoo. At the Market Square shore is Keisarinluodonlaituri (Kejsargrundskajen), named after an islet that the ship carrying emperor Nicholas I of Russia collided with in 1833. Nowadays the islet lies under filling ground brought to the shore. The pier is used mostly by the commuter ship to Suomenlinna. On the other side of the disused turning railway bridge is the Cholera basin, named after a seaman who died from cholera. The bay is used by fishermen and tourist ships. Next to the old market hall is the Vironallas (Estbassängen) bay,