The work to recover a passenger ship that sank more than a year ago began Wednesday with a survey of underwater conditions to decide how the ship will be pulled out of the water.

The survey is expected to take months as the country is trying to recover the ship without any serious damage to the vessel or any remains of people still missing from the tragic sinking, according to the Ministry of Oceans and Fisheries.

The 6,825-ton ship sank off the country's west coast on April 16 last year while en route to the southern resort island of Jeju.

The accident killed 304 people, mostly high school students on a school excursion. Nine of them still remain missing.

"The ultimate objective of the recovery plan is to find the missing people," the ministry has said.

The 85.1 billion won ($72 million) project to recover the ship, the Sewol, has been awarded to a Chinese consortium led by China's state-run Shanghai Salvage.

The consortium has said it will close all openings of the ship with nets to prevent any contents of the ship from slipping out.

Ministry officials earlier said the actual work to hoist the ship will likely begin early next year, with completion before the end of June. (Yonhap)