The U.S. Navy are temporarily barring civilians from operating equipment on submarines following the revelation that non-Navy personnel pulled the levers to surface a vessel in a manouvre that caused a fatal crash with a Japanese trawler.
Civilians on the USS Greenville nuclear submarine were at two control positions when it surfaced under Ehime Maru, a fishing boat carrying Japanese high-school students, while practicing an emergency procedure to thrust it to the surface off Hawaii.
The ship sank, leaving nine of the 26 people aboard missing, presumed dead.
A U.S. Navy spokesman also confirmed that civilians were not allowed to perform the maneuver which caused the submarine to strike the Ehime Maru.
The spokesman said the investigation into incident indicated that the presence of civilians at control stations or their presence on board had not caused the collision.
Two of the 16 visitors invited aboard the submarine for a brief training cruise were allowed to be at control positions, but in media interviews they have reiterated statements by Naval spokesmen that they were strictly supervised.
Preliminary results of a Navy investigation are expected soon.
Reuters