Laboratory data on the geometry of oscillation ripples, collected by a number of investigators using a variety of experimental devices, have been compared to determine differences among oscillating bed, wave flume and water tunnel devices. Additional data have been obtained employing a wave flume that generates large waves. It was found that ripples formed in oscillating-bed devices do not correspond well with those developed under progressive waves in flumes and in water tunnels. The remaining vortex ripple data, the class of ripples primarily formed under ocean waves, are found to correspond to the linear relationship, lambda = 0.65d o , where lambda is the ripple spacing and d o is the near-bottom orbital diameter. The data depart from this relationship as the orbital diameter increases, the departure occurring at higher orbital diameters as the grain size increases. A tentative diagram is developed relating the maximum possible tipple spacing to the median sand diameter.