States have to report impulsive noise events annually to these regional noise registries. D11C1 requires the consideration of three main aspects: the spatial distribution, the temporal extend, and the levels of impulsive underwater noise. The regional noise registries were developed to be able to include these aspects accordingly, but they use simpli?ed concepts (i.e., source strength classes and anthropogenic activity categories). The most common reported time resolution of impulsive noise events is on a daily basis, but an even lower reporting resolution is also accepted by the registries. The spatial information on events spans from the exact source location of an activity, to within standardized geographic polygons of different sizes. Finally, noise registries classify impulsive noise event according to ?ve noise level categories. The evaluation of noise registry data provided the basis for determining the practicable level of accuracy that can be achieved, which largely depends on both the availability and resolution of data collected in the regional noise registries. For this analysis, three publicly available regional databases were used that currently include datasets on impulsive underwater noise: the ICES noise registry for OSPAR and HELCOM regions (International Council for the Exploration of the Sea (ICES) n.d.), the QuietMed noise registry for the Mediterranean Sea region (Enguix et al. 2019), and the EMODnet database (EMODnet n.d.) with subsets of data from different regions (Fig. 1). Fig. 1 Visualization of publicly available data reported to regional noise registries 4 C. Juretzek et al.