Composite materials are used in many marine structures such as renewable marine energy conversion systems because of their fairly good mechanical properties and especially their low densities compared to traditional materials. The most advanced features currently available in finite element (FE) Abaqus/Explicit have been employed to simulate the behavior of the composite nozzle under hydrodynamic and impact loading. A hydrodynamic analysis was considered to design the nozzle turbine and the hydrodynamic pressure obtained was then implemented as boundary conditions to a FE code. The goal of this article is to evaluate the durability of composite materials of a ducted tidal turbine under critical loads (hydrodynamic and hydrostatic pressures) with the implementation of a failure criterion using the finite element analysis (FEA). The mechanical behavior was analyzed for two materials (Carbon–epoxy/ Glass–polyester). This has been accomplished by forming a user-created routine (VUMAT) and executing it in the ABAQUS software.