Common use of shipboard AIS creates conditions for the use of a new kind of dynamic data in the situationof the risk of collision. AIS position report is a source of supplementary information derived from errorleveraged radar measurement. However, in view of the results of the studies there are opinions with regardto inconsistent AIS dynamic data in the process of decision-making by the officer of the watch. By takinginto consideration the recordings of the studies and technical specification of AIS it can be concluded thatthe results of inconsistent data have significant role in collision avoidance manoeuvring.
