The system provides fire control for surface engagement with spotting corrections in both line and range and has an effective secondary self-defence anti-air capability.

The ship's Kelvin Hughes surface search radar, operating at E, F and I bands, is installed high on the main mast over the bridge.

A Brunvoll FU45 CPP bow thrusters, rated at 340 kW with 55 kilonewtons (12,000 lbf) of thrust, is fitted for precision manoeuvring and station keeping.

On 5 October 2004, Róisín was the first vessel on scene after the fire on board the Canadian Forces submarine Chicoutimi off the northwestern coast of Ireland.

[4] Róisín enforced a 200 m (220 yd) exclusion zone around the vessel Astrid which ran aground on 24 July 2013 near Quay Rock at Ballymacus Point, near the Sovereign Islands in southern Ireland, while attempting to enter the harbour near Kinsale, County Cork.

[7] Róisín took part in a surveillance operation of the yacht Makayabella in September 2014 before it was boarded 200 nmi (370 km) off Mizen Head and subsequently had €80M worth of cocaine seized.

[8] From May to July 2016 Róisin was deployed to the Mediterranean as part of a humanitarian mission during the European migrant crisis,[9] and was involved in the rescue of several hundred people from unseaworthy vessels.