Wave-structure interactions of flexible membrane-type materials are an emerging research field, driven by their potential in renewable energy and breakwater concepts. This study proposes stereoscopic digital image correlation (DIC) as a scalable method for spatiotemporal measurements of fluid-structure interactions in wave tanks. The scalability is presented by two setups with domain dimensions ranging from O(10−1 m) to O(101 m). The calibrations of 5 adjacent and synchronized stereoscopic camera pairs are projected on a common frame of reference to cover the large domain. The presented methodology includes suggestions on the calibration method, and a practical speckle application technique is proposed. The benefits of the method are highlighted by the preliminary indication of a dynamic scaling law for wave-structure interactions. This work can serve as a foundation for further development and application of stereoscopic DIC for such structures. It is expected that this large domain method will contribute to further physical understanding of the fluid-structure interactions of large floating structures in waves.