Merchant vessels may be used by SAR mission coordinator (SMC) according to SOLAS convention and other international conventions. Some vessels are more suitable than others due to construction, number of person on board, actual stability situation, etc. Actually SMC may use ship which declared readiness to attend SAR action only. Modern information systems give SMC information about other vessels in action area also. SMC is responsible to choose the best vessel for SAR action. The paper presents model of Bayesian network to estimate merchant ship usability for SAR action. Information from AIS system is very useful for this model. Combination AIS system with presented model gives SMC tool which will help to find the best ship in area. Some ship particulars are more important that other and may bring about that the ship will be not suitable for SAR action

Increasing accuracy of weather forecasts for ocean areas (wave factors, limits of ice), development of communication means, receiving and computations of navigational and weather information (satellite communication, computer programming) as well as development of theoretical basics of optimization and decision making process permit operational computations of optimal routes for ships on the oceans. Using dynamical programming, route selection is made objectively, taking into account dynamical changing weather conditions, ship characteristics and assumed optimization criteria. For computations different types of algorithms may be used: from graph theory, evolutionary algorithms based on genetic algorithms as well as isochrone ones. Following an example of results of ships voyages recommended by Polish Steamship Company routing centre, 3% of time voyage saving in comparison with seasonal voyages were obtained.

During ship design, service speed is one of the crucial parameters in determining the operational economy of the vessel. As sufficiently exact calculation methods applicable to preliminary design stage are lacking, the so-called contract speed, the speed which a ship reaches in calm water, is usually cited. Żelazny (2015) developed a parametric method for calculating total ship resistance under actual weather conditions (wind, waves, sea current). This paper presents a parametric model of a ship’s propulsion system (screw propeller – propulsion engine) as well as a method, based on both the resistance and propulsion system models, of calculating the mean statistical value of a ship’s service speed under the seasonal weather conditions occurring on shipping lines. The method makes use only of basic design parameters, and may be applied in preliminary design phase of container ships.