The sinking of Sewol resulted in widespread social and political reaction within South Korea. Many criticized the actions of the captain and most of the crew. Also criticized were the ferry operator and the regulators who oversaw its operations, along with the South Korean government for its disaster response (including the poor showing of the then Korean coastguard) and attempts to downplay government culpability.
On 15 May 2014, the captain and three crew members were charged with murder, while the other 11 members of the crew were indicted for abandoning the ship. An arrest warrant was also issued for Yoo Byung-eun, the owner of Chonghaejin Marine, which operated Sewol, but he could not be found despite a nationwide manhunt. On 22 July 2014, police revealed that they had established that a dead man found in a field 415 kilometres south of Seoul was Yoo. Foul play was ruled out.
At the time of her purchase by Chonghaejin Marine in 2012, the ship that would come to be known as the Motor Vessel (MV) Sewol was 18 years old and dilapidated. She was originally named Ferry Naminoue and was operated from 1994 to 2012 as a transport ship for cargo and passengers by the Japanese company A-Line Ferry.:9 According to A-Line Ferry, she did not experience any problems while being operated by the company in Japan. After she was purchased on 8 October 2012, she was registered by Chonghaejin on 22 October 2012 and underwent modifications from 12 October 2012 to 12 February 2013.:9 The modifications were later found to have been based on an illegal redesign of the ship.
After the modifications, which included the addition of two floors of passenger space and the expansion of the cargo space, Sewol had her gross tonnage increase by 239 tons to 6,825 tons and her persons capacity increase by 116 people for a total of 956 people including the crew.:11 The modifications also resulted in her center of gravity being moved upward by .51 m (1 ft 8 in):11 as well as a left-right imbalance. After the modifications were completed, she underwent investigations by the Korean Register of Shipping including an inclining test, and received the ship inspection certification and the certification for the prevention of sea pollution on 12 February 2013.:15 During the process of approving the modifications, the Register reduced the maximum amount of cargo that could be carried by 1,450 tons to 987 tons, and increased the amount of ballast needed by 1,333 tons, to 1,703 tons. The cargo limits were not known by the Korea Shipping Association, who has the responsibility to manage ferries, or the Korea Coast Guard, who were responsible for overseeing the Shipping Association. The South Korea government's Audit and Inspection Board later revealed that the Register's licensing was based on falsified documents. After the inspections, 37 tons of marble were further added to the gallery room at the bridge deck located on the back of the ship.:17
Sewol began operations on 15 March 2013. She made three rounds trips per week from Incheon to Jeju, each one-way voyage of 425 kilometres (264 mi) taking 13.5 hours to complete. On 19 February 2014, she received an interim inspection and a periodic inspection from the Register.:17 She had made the round trip a total of 241 times until the day of the incident.