I. Introduction
Most of the operational life of sailing vessels consists in tracking a predetermined path in restricted and open waters, according to complex traffic management constraints and risks [1]. The capability of forming convoys and following a leading target-vessel within its wake is a valuable feature in both blue seas and busy/restricted areas, such as inland waterways and harbors [2]. In this scenario, the two main challenges are to steer, while keeping off-track tolerances, and to tune the speed according to the leader. Such objectives need to be reached with high accuracy and are crucial to safely exploit the viable inland waterways' routes and minimize the sailing delays and accidents [3], [4].