A new approach for measuring ripples which usually cover the sea bed in the nearshore region is presented. The measurement system is based on a structured light technique which allows the contactless estimation of ripple characteristics and the analysis of time evolution of these bedforms. An experimental set-up which includes wave tank, laser sheet generation, video camera and image processing software has been realized. The new proposed procedure allows for obtaining effective estimations of both ripple amplitudes and ripple wavelengths when compared with traditional measurement methodologies. The results of this experimental investigation show in particular that, not only small ripples can be detected and measured with an uncertainty smaller than 1 mm, but even their time evolution can be analyzed.