A unified collision avoidance system is proposed to improve the efficiency and safety of marine transport, namely maritime avoidance navigation, totally integrated system (MANTIS). The principle behind its operation is to remove the difficulties and uncertainties involved in marine navigation through a system structure that makes marine transport deterministic rather than uncertain. Fundamental to its operation is a strategic interactive expert system that can determine safe and efficient navigation routes for all vessels as part of journey planning and en route collision avoidance. An important requirement is to take account of non-navigable areas, collision regulations, ship characteristics, sea state and sensor accuracy during evaluation. An outline of the MANTIS infrastructure is given, followed by a description of the vessel management system (VMES). Simulation results exemplify the significance of the system for future exploitation.