On board the open-topped yellow tour-boat RIB, an audio commentary firstly informs you about the M.V. Cill Airne, built nearby in the old Liffey Dockyard, nearly fifty year ago. Discover why she was one of the last riveted built vessels in Europe, her days as liner-tender and the rich and famous who threaded her decks.

Heading downstream the former lightship Kittiwake is berthed opposite the O2 Arena. She was one of the last lightships to serve in Irish waters at the South Rock station off Co. Down. In complete contrast a ferris-wheel revolves in the background but no sooner the boat slips under the East-Link Toll-Lift bridge which opened in 1984.

On the other side of the bridge a small non-descript looking grey-hulled motorboat lies at anchor, on her bow is painted the figure 11. So what's the story here!...here's a glue: 'Don't pay the ferry man until you get to the other side!...

Past Poolbeg Marina, giant blue-gantries cranes of the Marine Terminal Ltd (MTL) are busy unloading from Karin Schepers, a containership previously reported on Afloat.ie. Look out for the ports  'graffiti', the work of crews who make their mark by painting the name of their ship and also the mural of the late Ronnie Drew of The Dubliners.

Opposite this terminal is the ports largest basin, Alexandra Basin, named after Queen Alexandra. Subject to port security, the tour may include entering the basin should there be a particular vessel of note.This also allows for views of the dock-gates of the Dublin Graving Dock, one of only three large ship-repair facilities on the island of Ireland. Neighbouring the graving dock is where the Liffey Dockyard once stood.

Before the tour passes the towering twin stacks of the former ESB Poolbeg electricity power station is tucked away Pigeon Harbour. Learn more about its hotel conveniently sited beside where packet-ships regularly plied, essentially the ferryport of its day. Its modern-day counterpart faces opposite on the north quays where up to 17 sailings daily operate on the Irish Sea.

Marvel at the length of the impressive Great South Wall, why was it called 'Great' and why was it built?... What can be revealed is that Captain William Bligh of "Mutiny of the Bounty" fame was a major figure in the project, when the wall was completed in 1795.

The commentary has many more fascinating facts, figures and the occasional anecdote told with typical Dublin wit. So if you live within 80km (50-mile) radius of the capital, then the chances that the shirt you wear, the breakfast cereal you ate and the car you drive, most likely came through Dublin Port as almost 75% of goods serve this hinterland.

More on Dublin Bay here