GEWEXSRB_Rel4_1-IP_Longwave_3hrly_oceanonly is the Global Energy and Water Exchanges (GEWEX) Surface Radiation Budget (SRB) Integrated Product (Rel-4) Longwave 3-Hourly data product. It contains ocean-only global fields of 26 longwave surface, Top of Atmosphere (TOA), and atmospheric profile radiative parameters derived with the Longwave algorithm of the NASA World Climate Research Programme/Global Energy and Water-Cycle Experiment (WCRP/GEWEX) Surface Radiation Budget (SRB) Project. This version is an extension of Release 4-Integrated Product with ocean-only fluxes due to a missing key input from the main data set. The fluxes include all-sky, clear-sky, and pristine-sky TOA upward fluxes (outgoing longwave radiation, OLR), all-sky, clear-sky, and pristine-sky upward and downward fluxes at the tropopause, 200hPa, 500hPa, and surface. In addition to the fluxes, a day/night flag and a status flag of filled cloud properties are also included. Inputs to the longwave algorithm are cloud information based on ISCCP HXS, meteorology from ISCCP nnHIRS, SeaFlux SST and surface, and MERRA-2 conditionally. The temporal range is January 2010 through June 2017. Data collection for this product is complete.