This paper deals with the resilient control of a permanent magnet synchronous generator-based tidal turbine subjected to magnet failures. In this context, a magnetic equivalent circuit method is used to model the synchronous generator magnet failures. A fault-resilient controller is therefore derived for magnet failure resilience purposes. In fact, high-order sliding modes have been adopted to address the robustness problems faced by conventional techniques such as PI controllers. The proposed fault-resilient controller is evaluated and tested based on extensive simulations using real tidal velocities of the Raz de Sein site in Bretagne, France.