Rear Adm. Charles H. Griffiths Jr., who completed the initial investigation into the USS Greeneville accident, identified five factors he believes caused the accident:
Crew confidence in Cmdr. Scott Waddle "may have broken down the inclination ... to give him timely and forceful backup."
"An artificial urgency to get onto the surface toward the end of the day" led to a hasty sonar search and periscope sweep.
An understaffed crew, particularly an unqualified sonar technician who was poorly supervised, "handicapped" the sub.
A malfunctioning analog video signal display unit above a periscope should have caused the sub’s crew to be more deliberate in searching for surface ships before executing the "emergency blow," just before it crashed into the Ehime Maru.
Sixteen civilians on board blocked sailors’ views of control panels and the line of sight between crewmen and Waddle.
Griffiths made ten recommendations for further investigation:
Determining the eyesight of Waddle and the officer of the deck, Lt. j.g. Michael Coen. Both conducted periscope sweeps before beginning the emergency blow.
Soliciting testimony from some of the 16 civilians aboard the Greeneville that day and from Capt. Robert L. Brandhuber, the chief of staff of the Pacific Fleet’s submarine force, who was escorting the visitors.
Soliciting the views of naval leaders about civilian visitors aboard warships.
Evaluating the other sonar contacts the Greeneville was tracking besides the Ehime Maru.
Reviewing the search-and-rescue capabilities of submarines.
Evaluating the extent of the damage to the Greeneville.
Getting the U.S. Coast Guard’s assessment of the rescue effort.
Obtaining testimony from Capt. Fred Byus, commander of Submarine Squadron No. 7, who conducted the initial interviews with the crew of the Greeneville.
Conducting an active sonar demonstration to identify its limitations and advantages.
Interviewing Navy Capt. Thomas G. Kyle, a submarine technical adviser for the National Transportation Safety Board.
