Memorial at sea 

Relatives of victims of the Sewol ferry disaster react as they throw flowers to pay tribute to the victims of the 16 April 2014 sinking, at sea off Jindo Island, in the southwestern province of South Jeolla, 15 April 2015.

Relatives of victims of the Sewol ferry disaster react as they throw flowers to pay tribute to the victims of the April 16, 2014 sinking, in the sea off Jindo Island, in the southwestern province of South Jeolla, April 15, 2015.

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015.

A mother of a victim onboard sunken ferry Sewol cries as she attends a memorial ceremony, ahead of the first anniversary of the disaster, at a port in Jindo, April 15, 2015. Many of the children followed instructions to stay in their cabins as the crew scrambled to safety. REUTERS/Kim Hong-Ji

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015.

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015.

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. More than 300 people died in the disaster, with the bodies of nine still missing. REUTERS/Ed Jones/Pool

Relatives of victims onboard sunken ferry Sewol, react as they visit the site where the ferry sank in the sea off Jindo, ahead of the first anniversary of the disaster, April 15, 2015. REUTERS/Kim Hong-Ji

Relatives of victims of the Sewol ferry disaster stand on the deck of a boat during a visit to the site of the sunken ferry off the coast near the Jindo Island southwestern province of South Jeolla, April 15, 2015. REUTERS/Jeon Heon-Kyun/Pool

Mothers of victims onboard sunken ferry Sewol pay silent tribute as they attend a memorial ceremony, ahead of the first anniversary of the disaster, at a port in Jindo, April 15, 2015. REUTERS/Kim Hong-Ji

A relative of victims onboard sunken ferry Sewol, holds a flower as she visits the site where the ferry sank in the sea off Jindo, ahead of the first anniversary of the disaster, April 15, 2015. REUTERS/Kim Hong-Ji

Yoo Baek-Hyeong, wife of Danwon high school teacher Yang Seung-Jin who went missing in the Sewol ferry disaster, sits on the deck of a boat during a visit to the site of the sunken ferry off the coast near the Jindo Island southwestern province of South Jeolla, April 15, 2015. REUTERS/Jeon Heon-Kyun/Pool

A relative of victim of the Sewol ferry disaster reacts after throwing flowers to pay tribute to the victims of the 16 April 2014 sinking, at sea off Jindo Island, in the southwestern province of South Jeolla, 15 April 2015. REUTERS/Jeon Heon-Kyun/Pool

A relative of victim of the Sewol ferry disaster stands on the deck of a boat during a visit to the site of the sunken ferry off the coast near the Jindo Island southwestern province of South Jeolla, 15 April 2015. REUTERS/Jeon Heon-Kyun/Pool

Relatives of victims of the Sewol ferry disaster stand on the deck of a boat during a visit to the site of the sunken ferry off the coast near the Jindo Island southwestern province of South Jeolla, 15 April 2015. REUTERS/Jeon Heon-Kyun/Pool

A relative of victims of the Sewol ferry disaster weeps as she and others stand on the deck of a boat during a visit to the site of the sunken ferry off the coast of South Korea's southern island of Jindo on April 15, 2015. REUTERS/Ed Jones/Pool

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry off the coast near the Jindo Island southwestern province of South Jeolla, April 15, 2015. REUTERS/Jeon Heon-Kyun/Pool

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry off the coast near the Jindo Island southwestern province of South Jeolla, 15 April 2015. REUTERS/Jeon Heon-Kyun/Pool

Relatives of victims of the Sewol ferry disaster react as they throw flowers to pay tribute to the victims of the 16 April 2014 sinking, in the sea off Jindo Island, in the southwestern province of South Jeolla, April 15, 2015. REUTERS/Jeon Heon-Kyun/Pool

A mother of a victim onboard sunken ferry Sewol cries as she attends a memorial ceremony, ahead of the first anniversary of the disaster, at a port in Jindo, April 15, 2015. REUTERS/Kim Hong-Ji

Relatives of victims onboard sunken ferry Sewol, visit the site where the ferry sank in the sea off Jindo, ahead of the first anniversary of the disaster, April 15, 2015. REUTERS/Kim Hong-Ji

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. REUTERS/Ed Jones/Pool

A relative of a victim of the Sewol ferry disaster sits on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. REUTERS/Ed Jones/Pool

A relative of a victim of the Sewol ferry disaster hands out flowers to others on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. REUTERS/Ed Jones/Pool

Relatives of victims of the Sewol ferry disaster weep as they stand on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. REUTERS/Ed Jones/Pool

Family members of the victims of the sinking of the ferry Sewol visit the site where the ferry sank off Jindo, South Korea on the eve of the first anniversary of the disaster Wednesday, April 15, 2015. REUTERS/Ahn Young-joon/Pool

Relatives of victims of the Sewol ferry disaster sit on a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. REUTERS/Ed Jones/Pool

Relatives of victims of the Sewol ferry disaster take photos from the deck of a boat as they look out to a buoy marking the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. REUTERS/Ed Jones/Pool

A relative of victims onboard sunken ferry Sewol, cries as they visit the site where the ferry sank in the sea off Jindo, ahead of the first anniversary of the disaster, April 15, 2015. REUTERS/Kim Hong-Ji

A relative of a victim of the Sewol ferry disaster stands on the deck of a boat during a visit to the site of the sunken ferry, off the coast of South Korea's southern island of Jindo April 15, 2015. REUTERS/Ed Jones/Pool