Description: The bottle data on cruise MSM64 contain measurements of pressure, temperature, salinity and oxygen (derived from CTD values at the location of closing bottles) and direct measurements of oxygen, CFC-12 and SF6. The data were collected with the research vessel Maria S. Merian. Region: subpolar Northa Atlantic, 11°W-47°W, 47°N-54°N, Ports: Southampton - St. John's, Date: May 27 - June 23, 2017. The bottle data were collected by an SBE 32 water sampler system in connection with a SBE 911 plus CTD. CTD was mounted to a metal frame with 22 Niskin bottles of 10 l volume, which was lowered from the sea surface down to 10 m above the seafloor. Pressure, temperature, salinity and oxygen data from the CTD were recorded at the time when closing the bottles. In addition, direct samples of salinity and oxygen from the water bottles have been taken to calibrate the CTD data. The accuracy of the CTD measurements is: 1 dbar for pressure, 0.001 °C for temperature, 0.002 for salinity, 3.5 µmol/kg for oxygen. The oxygen samples from the Niskin bottles have been analysed by Winkler titration with an accuracy of 3.0 µmol/kg. In addition, samples for the analyses of CFC-12 and SF6 in the home lab have been stored in flame sealed glass ampoules of two sizes: ~100 ml and 220 ml. The samples have been analysed in the tracer lab at the University of Bremen (department of oceanography) by a capillary-chromatographic system with electron capture detector. This device is an advancement from the one described in: Bulsiewicz, K., H. Rose, O. Klatt, A. Putzka, and W. Roether (1998), A capillary -column chromatographic system for efficient chlorofluorocarbon measurement in ocean waters, J. Geophys, Res., 103, 15959-15970. CFC-12 and SF6 values are reported on the SIO-98 scale. Accuracy is 4% for SF6 and 2% for CFC-12, detection limt 0.02 fmol/kg for SF6 and 0.004 pmol/kg for CFC-12 (values are slightly better for the samples from the large ampoules).