Observations in the Denmark Strait are an integral part of the two German research projects, "Regional Atlantic circulation and global change - RACE" and "Energy transfer in the atmosphere and ocean - TRR181". Through Denmark Strait, a plume of dense water from the Nordic Seas crosses the ridge system between Greenland and Iceland and enters the North Atlantic Ocean. This ‘overflow’ plume has been monitored at the sill of the strait with moorings since 1996. In order to service the long term moorings and capture mixing processes downstream, cruise 64PE426 was carried out in September 2017 with RV Pelagia. The goals of the cruise were (I) obtaining data in the region of intense mixing, where ambient water is entrained into the overflow plume, and (II) continuing the monitoring of the Denmark Strait Overflow transports at the sill of Denmark Strait. Ship-borne measurements (CTD, ADCP) were conducted and a short-term mooring program was realized. Furthermore, existing moorings were serviced (see picture below). The cruise started on 11th of September in Reykjavík, Iceland. Transit to the working region was 24 hours. Planned were 12 working days. However, an accident of one scientist demanded a short port call after only 10 hours of measurements. Later on, two storms hindered station work in the area and forced a return to Reykjavík already on 23rd of September. Nevertheless, important data were collected during the cruise. The mooring work was in the focus of the working plan and all tasks were completed successfully.