The structural design of tidal turbine blades is governed by the hydrodynamic shape of the aerofoil and extreme loading. The design of the aerofoil, chord and twist distribution along the blade, is generated so that the turbine has the optimum performance over the life time. Structural design gives the optimal layout of composite laminae such that the ultimate strength and buckling resistance requirements are satisfied while ensuring that certain fabrication criteria are satisfied. However, the structural design is using only static extreme loads while there is a lack of dynamic loads-based fatigue design of the tidal blades. In that regard the approaches for tidal turbine material fatigue life are studied.