Water samplers, CTD's, a fluorometer and a thermistor string are fixed to a permanent mooring in the north-western Irish Sea. This mooring is out of range of GSM networks for data telemetry, therefore data is downloaded directly at each service. Service intervals are typically 6 weeks, when instruments are cleaned, serviced, and waster samples collected for nutrient analysis - work is carried out aboard the RV Lough Foyle. The mooring is positioned at 53º 47' N / 05º 38' W in an area that forms an important part of the Irish Sea prawn (Nephrops norvegicus) fishery. A trawling exclusion zone has been established around the mooring in order to protect the integrity of the mooring and instruments. In the spring and summer, solar heating in combination with weak tidal flows allow thermal stratification to develop in this area west of the Isle of Man. This stratification and its associated fronts ensure that large differences in water temperature occur over short distances and depths, and isolates a dome of colder water in a topographical depression. The density gradients between the cold water dome and warmer surrounding mixed waters drive a cyclonic gyre.