The article considers the organization of the functional complement of the global navigation satellite system (GNSS) for the tasks of ensuring unmanned navigation in the port of Novorossiysk. The task of the study is to calculate and display the dynamics of unmanned vessels based on adjustments of the marine differential subsystem of the functional complement of control and correction stations (CCS) and calculations of free-form inertial navigation system (FINS) in the algebra of quaternions. The purpose of the study is to develop algorithms and computing tools for unmanned vessels based on the quaternion model. The paper presents the results of calculating the position and dynamics of the vessel with clarification on the functional additions of satellite navigation to existing GLONASS CCS. The existing CCS at Doobsky Cape provides a functional complement to GNSS by means of corrective corrections to pseudo range up to 150 nautical miles. However, for high-precision navigation to ensure safe navigation in the port of Novorossiysk due to the terrain, it is not always possible to identify accurately a vessel due to the visibility of satellites. It is planned to improve the accuracy of determining the vessel and the parameters of its movement by introducing a functional addition in the coastal segment of the management of unmanned navigation.