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