The ability to quantify unsteady loading on tidal turbine blades will aid the design of blades which can withstand the harsh marine environment for up to 25 years. A model which utilises linear 2D analytical theory is used to test the combined effects of waves and turbulence with shear and tower shadow. Initial results show that the unsteadiness is mostly dominated by shear, unless the blade is incident to very-low frequency, large eddies or long waves.