The benefit of the Loran ground-based radio navigation system as an alternative to global navigation satellite systems is argued. The motivation of searching for a duplicate variant is caused by the necessity to ensure the reliability of positioning as a subject of countering spoofing and jamming risks when implementing the concept of cybernetic awareness on water transport. Hypothetically, the possibility of using e-Loran on the Northern Sea Route as a backup navigation system is considered. The experience of operating pilot projects of the enhanced Loran in the issue of the predicted potential of positioning accuracy is analyzed. The optimal method of compensation for the system error of geolocation based on the use of additional secondary factors is investigated. Taking into account the principle of the d-Loran functional, based on comparing the measured values of the radio signal passage delay with published analogues for transmitting clarifications to marine consumers, the necessity of using integrity as a criterion for a confidence assessment of the navigation information processing reliability has been determined. A critical analysis of the attempts effectiveness to use the linear interpolation method to calculate intermediate representative values of the delay in the radio signal transmission in order to simulate the map of additional secondary factors is performed. The hypothesis of the prospects for the isosurface corrections synthesis based on B-spline approximation is put forward. The South Korean experiment of synthesizing a chart of additional secondary factors with measured indicators of the radio signal propagation time delay in nanoseconds from the Pohang transmitting station has been repeated at the correct algorithmic level. In order to demonstrate the practical feasibility of the spline algorithm, a computer visualization of a cartographic fragment of additional secondary factors of Yongil Bay is performed. It is suggested that three-dimensional representation of the additional secondary factor for situational perception by the Officer on watch of map-aided correction as a process in alternative positioning in order to increase the reliability of location control through visual evaluation of proper use of corrections of the e-Loran differential variant. The prospect of using the developed package of applied Pascal-programs with implementations on display-type monitors as intellectual support for decision-making by the navigator in a posteriori assessment of the observation accuracy due to the visual representation of the correction field is noted.