Touted as the world’s longest river cruise, MV Ganga Vilas, has been docked at a Kolkata jetty and will on Monday leave for Sundarbans, a UNESCO heritage site, an official said. The cruise vessel, flagged off by Prime Minister Narendra Modi on January 13, entered West Bengal early this week through Murshidabad and later reached Kolkata, he said. The ship has been docked at the Indenture Memorial (IM) Jetty on the bank of the Hooghly river.