"Maybe we should blame the Norwegians," says Allan. "They built the iceberg."
Although there is currently no Titanic museum in Belfast - or indeed a maritime museum to acknowledge the 3000 other vessels built here - the city has long since come to terms with the notoriety of the great "unsinkable" ship. In fact, after those decades of denial by silence, Belfast is celebrating the Titanic and the city's maritime history with an annual festival in April.
There are also walking tours of the Titanic Dock and through the Edwardian pump house (which has a café and visitors' centre with audio-visual displays and works by leading Irish artists).
The Titanic Times - a thin broadsheet of anecdotes and photographs - says in its April editorial: "Belfast doesn't cower in the shadow of Titanic's untimely doom. Belfast basks in the glow of her everlasting accomplishment."
Those four days of carefree sailing, I suppose.
But the way to see the former shipyard area along the River Lagan is by boat, and so one afternoon I, along with only half a dozen others, took the Titanic Boat Tour from Donegall Quay for an information-packed and thoroughly enjoyable hour in which nothing happened and there was almost nothing to see.
All that remains of where the hull of the Titanic was launched from in May 1911 is an old crane: the dock in which she was constructed has long since been abandoned; the ship-building is now non-existent; and Queens Island, known as The Titanic Quarter, is the subject of a $7 billion redevelopment to be opened in time for the centennial of the sinking in April 2012.
In the shadow of two massive Harland and Wolff cranes, Samson and Goliath, will be an entertainment precinct, museums, hotels, restaurants and bars.
As with rivers and harboursides everywhere, new apartments and townhouses are springing up. People are coming back to this area - and the salmon are also returning to the Lagan: the sculpture of "the Big Salmon" on the quay celebrates the fact.
There is also much to learn from Allan, who keeps up a non-stop commentary punctuated by jokes and information as we putter down the Lagan: that 95 per cent of the photos of the Titanic are actually of the Olympic because that was the first White Star Line vessel, so why bother taking a photo of the second?
He notes that the massive Titanic - 270m long - wouldn't even be in the top 3000 big ships today, and that the fourth funnel on the ship wasn't actually functional. It was put there to make it look more powerful.
And then towards the end of the hour, we pull up alongside the hull of the Nomadic, which was "the Titanic in miniature, used to transport the First Class passengers out to the ship", says Allan.
It is a sad-looking affair, not rusting so much as sorry and abandoned. But, like this whole area, it is currently undergoing a renovation.
A refit will take the Nomadic back to the days when men and women in their finery stepped aboard and were transported to the unsinkable Titanic ... for four days of carefree sailing.
CHECKLIST
Getting there: Cathay Pacific offers daily flights from Auckland to London via Hong Kong. Special fares are available. RyanAir flies to Belfast depart from Stansted.
Titanic Tours: See titanicboattours.com or titanicsdock.com.
Further information: You can get general information on visiting Britain and Northern Ireland at visitbritain.co.nz and discoverireland.co.nz.
Graham Reid travelled to Britain courtesy of Cathay Pacific and discoverireland.co.nz