A multi-channel seismic dataset was acquired during RRS James Cook cruise JC152 (August - September 2017), around the Scanner Pockmark Complex in the North Sea. Data were recorded using a number of different seismic sources, comprising: 1) a GI airgun array, used in two different configurations for separate parts of the survey, i) a 420 ci (2 x 105/105 ci) array operated in harmonic mode and fired at 8 s intervals, and ii) a 300 ci (2 x 45/105 ci) array operated in true GI mode and fired at 6 s intervals, both towed at 2 m depth below sea surface; 2) an Applied Acoustic Engineering Squid sparker (1750 or 2000 J), towed at the sea surface and triggered at 2 s intervals, and; 3) a Duraspark sparker (2000 J), towed at the sea surface and triggered at 2 s intervals. Signals produced by the GI airguns and surface sparkers were recorded on two towed multi-channel streamers: a) a 60 channel, 1 m group interval streamer recorded on a Geometrics Strataview R60 recording system, and b), a 120 channel, 1.56 m group interval GeoEel streamer, at sampling rates between 0.125 and 0.5 ms depending on the streamer and source pairing. Data are provided in standard SEG-D format. The data were acquired as part of the 'Characterization of major overburden leakage pathways above sub-seafloor CO2 storage reservoirs in the North Sea' (CHIMNEY) project, funded by the Natural Environment Research Council (NERC) under grant reference NE/N016130/1.