The purpose of a voyage data recorder (VDR) is to maintain
a store, in a secure and retrievable form, of information concerning
the position, movement, physical status, command and control of a
ship over the period leading up to and following an incident having
an impact thereon. Information contained in a VDR should be made available
to both the Administration and the shipowner. This information is
for use during any subsequent safety investigation to identify the
cause(s) of the incident.