1.   A monitor allowing the commander and the officer of the deck to view sonar data from the periscope stand was not working.

2.   As fire control technician, Seacrest takes sonar data and does a computer analysis to develop a detailed picture of the location and distances of other vessels.

3.   He noted a crewman who analyzes sonar data knew the Ehime Maru was nearby and never told Waddle.

4.   He said investigators might be able to retrieve sonar data from computer hard drives.

5.   The inaccurate course may have been due to a submarine maneuver that makes sonar data less reliable.

6.   The mistakes ranged from the submarine rushing to get back on schedule to vital sonar data not getting to the skipper.

7.   The sonar data is downloaded when the drone returns to the mother ship.

8.   They did not allow enough time for a thorough analysis of sonar data nor did they look through the periscope long enough or at raise it high enough.