Deployment of a sub-surface mooring at South Rockall (52° 59.956' N, 15° 31.16' W) from the RV Celtic Explorer survey CE18015 on 02/10/2018. Recovered on 28/05/2019 by the RV Celtic Explorer survey CE19009. The purpose of this activity is to collect data to help understand the variability in the water column not visible at the surface and provide context to CTD profile data collected in the South Rockall Trough. These data are vital in understanding the likely impact of future ocean climate scenarios on key marine sectors as well as understanding possible impacts on ecosystem in the North East Atlantic Ocean.