A collision at sea involving a passenger vessel raises the potential for greater loss of life and the ramifications are far more extensive. In the event of a collision in which a tanker is involved, keeping the two ships close together without tearing damaged metal structures apart could possibly prevent ignition of the tanker cargoes' vapours. The principle of marine 'black box technology' has come about because of the transport relationship with the aviation industry, which has been operating with black box technology on all passenger aircraft for many years. The International Marine Organisation (IMO) has stipulated the data that voyage data recording (VDRs) are expected to record, which includes the following: ship's position and speed, status of watertight and fire doors, engine orders and responses and so on. The Master of a ship involved in a collision incident would also consider making a Note of Protest through a 'Proper Officer' such as the British Consul.