İDO Istanbul Fast Ferries Co. Inc. (, meaning Istanbul Sea Buses) was founded in 1987 by the Istanbul Metropolitan Municipality. Originally established with a fleet of 10 seabuses built by the Kvaerner Fjellstrand shipyard of Norway, the İDO today has a fleet of 25 seabuses (with capacities ranging from 350 to 450 passengers) designed by Kvaerner Fjellstrand, Austal and the Damen Group; 10 high-speed car ferries (1200 passengers and 225 vehicles) designed by Austal and the Damen Group; 18 car ferries; 32 commuter ferries; and 1 large passenger ship.<ref n[2] At present, the İDO is the world's largest commuter ferry operator with its 87-passenger ships and 86 piers.<ref nam The company owns a total of 103 ships including its service vessels.<ref nam
In 2011, the company was privatized for 30 years by the Istanbul Metropolitan Municipality. {{c[3]
Fare system
The İDO uses several systems to manage trip fare. Since the conventional boats are scheduled on intracity lines and are roughly connected with other rapid transport systems such as the Istanbul Metro and İETT Buses, passengers simply pass through pay gates. There is no pre-reservation or assigned seating, and admission is fairly cheap.