This paper is concerned with the development of a fatigue life prediction methodology for ocean energy structures. To this end, a programme of fatigue testing of glass fibre reinforced laminates is employed to characterise the strain-life behaviour of two candidate material combinations. The test specimens are made from quasi-isotropic laminates of both vinyl ester and epoxy matrices. A preliminary finite element model of a tidal turbine blade is developed to identify the relevant stresses and strains under representative hydrodynamic loading. The hydrodynamic (blade) loads are calculated using a stream tube momentum model, based on tidal current velocities predicted by a sinusoidal equation. The comparative behaviour of the candidate materials is assessed in the context of the turbine blade model.