Deep-water divers on Thursday began search operations at the site of a tour boat that sank off Hokkaido in April, aiming to determine the cause of the deadly accident and find those who are still missing.
The divers will conclude the task of searching for the 12 people still unaccounted for as early as Friday, according to the Japan Coast Guard.
They are using a special technique known as saturation diving, in which they absorb a mix of oxygen and helium so they can adjust to the level of water pressure at the depth they intend to work at.
The divers are then slated to carry out a survey to prepare for the raising of the 19-ton Kazu I, which was carrying 26 people when it disappeared off Shiretoko Peninsula on April 23. Fourteen bodies have been recovered with no survivors. The boat is currently located about 120 meters below the surface.
It is the first time that divers have been involved in the survey of Kazu I. An underwater drone has been used for that purpose but none of the missing people were found inside. The divers' vessel, operated by Nippon Salvage Co., arrived at the site early Thursday.
Planes and ships have also been used by the coast guard in their search for the missing people, with local police expanding their search on land to areas south of the peninsula.
The tour boat was carrying 24 passengers and two crew members when it made a distress call and vanished after leaving Utoro port in Shari for a sightseeing trip along the scenic peninsula, despite bad weather being forecast.
