History of the Irish Naval Service started, and the ships were named "Cliona", "Maev" and "Macha". These three ships were to become a key part of the Naval Service in the 1950s and 1960s. The first formal training of Irish Naval Cadets took place at the Britannia Royal Naval College, Dartmouth, UK in 1947. Between 1968 and 1970, Cliona, Maev and Macha were withdrawn from service. These were replaced by three minesweepers commissioned in 1971: Grainne, Banba and Fola. In 1971 the Naval Service commissioned Verolme Cork Dockyard to build an offshore patrol ship. Named L.É Deirdre, it was the first naval vessel purpose-built in Ireland
Old Royal Naval College of its buildings are open to visitors. The buildings were originally constructed to serve as the Royal Hospital for Seamen at Greenwich, now generally known as Greenwich Hospital, which was designed by Christopher Wren, and built between 1696 and 1712. The hospital closed in 1869. Between 1873 and 1998 it was the Royal Naval College, Greenwich. This was originally the site of Bella Court, built by Humphrey, Duke of Gloucester, and subsequently renamed Palace of Placentia by Margaret of Anjou, wife of Henry VI, upon its confiscation. Rebuilt by Henry VII, it was thenceforth more commonly known as Greenwich Palace.