Here we provide simulated seasonal (DJF and JJA) sea surface temperature (THO), sea surface salinity (SAO) as well as surface zonal (UKO) and meridional (VKE) ocean currents velocities. THO and SAO are provided on the regular grid in 360x180 resolution while UKO and VKE on the curvilinear grid in 122x101 resolution (which is the resolution of the ocean component MPIOM). The simulations were produced with COSMOS in a coupled atmosphere-ocean configuration. All of the simulations were run with 4 x pre-industrial (PI) CO2 level (1120 ppm). The experiments differ by alterations in gateway configurations between the Arctic Ocean and North proto-Atlantic Basin. Our spin-up experiment (C-1120) employs Maastrichtian (~70 Ma) paleogeography of Markwick and Valdes [2004, doi:10.1016/j.palaeo.2004.06.015]. The experiment was run to the model year 10 600. Two other experiments were branched off from C-1120 from the model year 9200. One of them differs from C-1120 by the closure of Hudson Seaway (HUD-0) and was run for the next 1400 years. The other one (GNS-47) has each gateway between the Arctic Ocean and North proto-Atlantic basin closed apart Greenland-Norwegian Sea and was run for the next 2100 years. More information about the geological background and COSMOS configuration can be found in Radmacher et al. [2020, doi:10.1127/nos/2019/0527].