A 21 year (1998–2018) continuous monthly data set of the global distribution of light (photosyntheti-cally available radiation, PAR, or irradiance) reaching the seabed is presented. This product uses ocean color andbathymetric data to estimate benthic irradiance, offering critical improvements on a previous data set. The timeseries is 4 times longer (21 versus 5 years), the spatial resolution is better (pixel size of 4.6 versus 9.3 km at theEquator), and the bathymetric resolution is also better (pixel size of 0.46 versus 3.7 km at the Equator). The paperdescribes the theoretical and methodological bases and data processing. This new product is used to estimate thesurface area of the seafloor where (1) light does not limit the distribution of photosynthetic benthic organismsand (2) net community production is positive. The complete data set is provided as 14 netCDF files available onPANGAEA (Gentili and Gattuso, 2020a, https://doi.org/10.1594/PANGAEA.910898). The R packageCoastal-Light, available on GitHub (https://github.com/jpgattuso/CoastalLight.git, last access: 29 July 2020), allows us(1) to download geographical and optical data from PANGAEA and (2) to calculate the surface area that receivesmore than a given threshold of irradiance in three regions (nonpolar, Arctic, and Antarctic). Such surface areascan also be calculated for any subregion after downloading data from a remotely and freely accessible server