The standard for interfacing marine electronic devices (NMEA – National Marine Electronics Association), does not provide unambiguous information regarding the reliability of data and its timing. In this paper, time delays in navigational data are investigated. For this purpose AIS and navigational data collected offshore and onshore are used. The investigations are concentrated on lags among various NMEA sentences recorded in a relational database during the survey voyage. The analysis is based on standard elements of descriptive statistics

The Automatic Identification System (AIS) is widely used for reporting vessel movements and broadcasting additional information related to the current voyage or constant parameters like the IMO number or the overall dimension of the hull. Since dynamic AIS data is shared mostly without human interaction, and is not flawless, the static AIS content edited manually is vulnerable to human error. This work introduces a simple vessel motion pattern approach that determines the probable foredeck/afterdeck location of the GNSS reference used by the AIS transponder, and compares it to the hull parameters obtained from the static AIS data, to find observable errors in the static AIS configuration of the mount point of the GNSS reference antenna.