Abstract: A vessel tracking system may be used to detect and report an alert condition of a vessel (e.g., an aircraft). A vessel tracking system may monitor one or more travel (e.g., flight) characteristics of a vessel. At least one of the travel characteristics may be compared to one or more normal flight characteristics to assess an alert condition of the vessel. In some embodiments, the alert condition of the vessel may be reported (e.g., visually reported on a display). The alert condition of the vessel may be changed if at least one of the travel characteristics deviates from at least one normal travel characteristic. In certain embodiments, a boundary condition of an alert for the vessel may be modified if at least one of the travel characteristics deviates from at least one normal travel characteristic.