The Port of Belfast is Northern Ireland's principal maritime gateway, serving the Northern Ireland economy and increasingly that of the Republic of Ireland. It is a major centre of industry and commerce and has become established as the focus of logistics activity for Northern Ireland. Around two thirds of Northern Ireland's seaborne trade, and a quarter of that for Ireland as a whole, is handled at the port which receives over 6000 vessels each year.
Dublin Port is Ireland's biggest sea port. It has both historical and contemporary economic importance. Approximatively two-thirds of the Republic of Ireland's port traffic goes via Dublin Port. Recently, the port and its land, mostly at the eastern end of Dublin's Northside, were valued at €25 billion - €30 billion.
The Port of Cork provides pilotage and towage facilities for vessels entering Cork Harbour. All vessels accessing the quays in Cork City must be piloted and all vessels exceeding 130 metres in length must be piloted once they pass within 2.5 nautical miles (4.6km) of the harbour entrance.