A 50m euros (£41m) vessel has been handed over to the Irish Naval Service at a Devon shipyard.
The 295ft (90m) craft, called the Samuel Beckett, is the first completed ship to be built at Appledore Shipyard, near Bideford, since 2002.
The Irish Navy ordered two vessels from the shipyard in October 2010 for 99m euros (£81m). The second, called the James Joyce is still being built.
The Samuel Beckett will be used for fisheries and coastal protection.
Since 2002, the shipyard has built only parts of vessels, which have been floated away for other yards to complete.
Stuart Fegan from the GMB Union said he had concerns about future work coming to the yard.
He said: "We welcome the decision of the UK government over the decision to commission a new research vessel and certainly hope Babcock who operate Appledore will tender for that work."
The new ship, which weighs almost 2,000 tonnes, can hold 54 people.
The shipyard was founded in 1855, but went into administration in 2003.
The yard was then bought by engineering contractors Babcock.