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.

[5] The engines drive two shafts with Lips inboard turning controllable pitch propellers via single reduction gearboxes.

A Brunvoll FU45 CPP bow thruster, rated at 340 kW with 5.6 t (55 kN) thrust, is fitted for precision manoeuvring and station keeping.

[6] In February 2002, 5 months after she was commissioned, Niamh departed from Haulbowline on the most ambitious deployment ever undertaken by an Irish Naval Service vessel; initially tasked with resupplying Irish Army troops deployed as part of the United Nations Mission in Ethiopia and Eritrea, she subsequently undertook a cruise to a number of nations in Asia as part of the Irish government's overseas trade promotion strategy visiting Hong Kong, Incheon, Shanghai, Tokyo and Penang over a four-month period.

In November 2008 Niamh played an important role in the seizure of €750 million of cocaine off the Irish coast as part of Operation Seabight.

[9] Niamh took part in a surveillance operation of the yacht Makayabella in September 2014 before it was boarded 200 miles (320 km) off Mizen Head and subsequently had €80m worth of cocaine seized.

[11] This included a significant incident when Niamh was first to respond to the capsizing of a boat carrying hundreds of migrants off the coast of Libya.