The latest order forms part of a €100m ($129m) contract signed in 2010 for two vessels, with an option for a third.
Aimed at replacing the navy’s ageing fleet of OPVs, the new €54m vessel will be identical to the recently commissioned LE Samuel Beckett and the LE James Joyce, which is currently under construction.
An Taoiseach and Minister for Defence Enda Kenny said that the recent commissioning of LE Samuel Beckett highlighted the necessity to continue with the vessel replacement strategy.
"The new ship is impressive and offers excellent value, and I am convinced that this is the right time to maintain the momentum with the replacement strategy and move forward with a placing of a contract for the third patrol vessel," Kenny said.
By taking up the option in the contract, the navy will be able to purchase the OPV under 2012 prices, with scheduled delivery in 2016.
"The naval service carries out a wide range of challenging roles," Kenny added. "Naval service ships assert the integrity of our territorial waters, as well as protecting the marine resources of the country."
The 90m-long OPV can accommodate a crew of 54 and cruise at a maximum speed of 23k. It is integrated with a 76mm cannon, two heavy machine guns and four general purpose machine guns.
Image: The Irish Naval Service’s first OPV LE Samuel Beckett during sea trials. Photo: courtesy of Babcock International Group PLC.