VDR is the equivalent of a blackbox in an aircraft. It captures all the information about an accident at sea, such as the date, time as well as the location, speed and course of the ship. The information recorded can be used in identifying the potential hazards to safety and to improve operational procedures.
According to IMO regulations, the standard VDR is required to store a wide range of information. These include dates, times, and Coordinated Universal Time, vessel position (latitude and longitude, coordinate reference) along with heading and velocity, audio messages from the bridge (voice messages recorded with one or more microphones placed on the bridge for recording conversations and audio http://www.digitaldealdataroom.info alerts) and Very High-Frequency Radio Communications (VHF), and radar data (a faithful reproduction of the display visible at the time of recording) Rudder and engine position and watertight door status and accelerations.
The system consists of a concentrator that processes and encodes data streams, sensors which input data to the concentrator and an end-to-end recording media (FRM) which is able to survive accidents and allow for the recovery of voyage data. The FRM can be fixed to the vessel or a retrievable floating unit linked to EPIRB to allow for early detection in the event of an accident.
The most effective method to ensure the integrity of an vdr system would be to make its use an integral part of all bridge drills and training of the crew. The saved data may also be used to determine areas that require training and to improve bridge procedures and operational security.