Deployment of a sub-surface mooring at South Rockall (53° 0.94362' N, 15° 32.182' W) from the RV Celtic Explorer survey CE23009 on 11/05/2023. Recovered on 22/05/2024 by the Tigers II. Initial recovery attempted on 24th April 2024, however the buoy never surfaced. 2023 Mooring came to surface on 18th May and Novatech Beacon started pinging. Recovered by Tigers II fishing vessel on 22nd May. All equipment recovered successfully. 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.