There are two new navigational systems introduced by the International Maritime Organization
(IMO) during last few years useful for ships’ monitoring purposes as additional source of information
about vessels, supplementary to that derived from visual observation, shore based radar, radar tracking
aids and VHF voice communication. These systems are: Long Range Identification and Tracking (LRIT)
and Automatic Ship Identification (AIS). Each one of them has some advantages and faults. Paper
presents short description of these systems and vessel traffic services established in the Polish maritime
areas, assessment of information available from AIS shore based monitoring system and its comparison
with data derived from radar and radar tracking aids