It has been assumed about the hypothetical possibility of independent control of the ship isolinear movement in the presence of special equipment on board that can constantly determine the values of the parameters of the navigation isoline, taking into account the changing of geometric characteristics. It is possible that the sequence of approximated navigation data can be an argument for calculating continuous values of the true course with synchronous transmission of commands to the steering wheel to ensure adaptive self-regulating movement of the vessel. The need to use the approximation of navigation functions is justified by the expert ability for the fast calculation the functionals of analytical inflections of spline isolines, interpreted in mathematics as characteristic points of changing the signs of derivatives, but corresponding in practical application to the signals of automatic command submission to ship controls in the form of a rudder and a telegraph. The technology of using spline functions for navigation through geophysical fields is considered on the specific example of reconstructing the chart of the anomalous gravity field in Peter the Great Bay from the data of trajectory measurements of an autonomous uninhabited underwater vehicle. Computer simulation of gravimetric procedures based on a hybrid algorithm of two-dimensional B-spline approximation as a reference geophysical field for matching with the data of measurement studies is performed. As a proof of the efficiency of the proposed approach, a three-dimensional synthesis of a fragment of the field of gravity anomalies in the Japanese Sea region is implemented. It is noted that computer visualization of the 3D format of the programmed ship movement provides the possibility of intellectual assistance to the navigator in the strategy of instantaneous determination of the ship position under any circumstances of navigation. The approved spline algorithms can serve as harmonized support for the sefarer's staff when making a competent decision on the management of the vessel in any emergency situation. The theoretical possibility of practical application of the theory of spline functions to the approximation of the newest isolines, the introduction of which in the navigation of the future is associated with the innovations of technical means of navigation, is predicted. It is assumed that isolinear passages through geophysical fields can be effectively used in the unpredictable conditions of modern shipping, under various force majeure circumstances and natural disasters, and become a real autonomous alternative to the satellite navigation.