Marine casualty investigation has changed dramatically in recent years due to the expansion of electronic navigation.
In olden days, investigation of marine casualties relied heavily on the experience of the investigating officer. Statements of witnesses, who were almost always interested parties, were incomplete, self-serving, and often contradictory. Even the positions of involved ships immediately prior to the casualty could frequently not be determined with needed accuracy. This has largely changed with the advent of electronic navigation. Vessel traffic systems (VTSs) are in place in most busy ports. They record radio calls, radar signals, and, increasingly, AIS transmissions. On the vessels, ECDIS is being placed on ships of any significant size. While the major feature of ECDIS is the replacement of paper charts, a secondary feature is its ability to record time, position, heading, speed, and other relevant data. The voyage data recorder, similar to the black box utilized by commercial aircraft, is largely intended for use in marine casualty investigation. The full version of the VDR keeps a record of information received electronically and automatically from, among other things, the GPS, radar, gyro-compass, speed log, auto-pilot, echo sounder, rudder indicator, engine data logger, anemometer, alarm panel, fire door/watertight door control board, hull door position indicator, and hull stress monitoring equipment. In addition, it records information received from microphones positioned on the navigation bridge. Nowadays, one of the first demands of a marine casualty investigator is for full access to the ship’s ECDIS and VDR. The data obtained from these instruments frequently makes the investigation very straight-forward. For example, the investigation of the 2007 allision of the container ship Cosco Busan with the San Francisco-Oakland Bay Bridge was simplified when the course, speed, and position of the ship were pinned down, as well as the confusion on the bridge in the period preceding the allision and the incriminating statements recorded immediately thereafter. The world has shifted, yet again.