<p>This paper presents an adaptive fuzzy prescribed-time fault-tolerant tracking control framework for underactuated surface vessels subject to unknown external disturbances and actuator bias faults. The proposed method integrates adaptive fuzzy estimation with prescribed-time control and a coordinate-transformation-based decoupling mechanism to simultaneously address underactuation and fault effects in a unified framework. An adaptive fuzzy estimation law is developed to estimate the unknown bounds of external disturbances and actuator bias faults without requiring prior information. By incorporating this estimation mechanism into a prescribed-time control design, all tracking errors are guaranteed to converge to a small neighborhood of the origin within a user-defined time, independent of initial conditions. Rigorous Lyapunov analysis establishes the stability and fault-tolerant properties of the closed-loop system. Although the proposed control scheme is developed for underactuated surface vessels, the overall framework is generic and can be extended to a broader class of nonlinear underactuated systems with disturbances and actuator faults. Simulation results demonstrate that the proposed control strategy achieves faster convergence and higher tracking accuracy than existing methods.</p>