QM2 welcomed to Sydney

Thousands have come out to see the Queen Mary 2 — the world's biggest ever passenger liner — sail into Sydney Harbour, where it will later rendevous with sister ship the QEII.

Followed by a flotilla of boats and watched by huge crowds, the world's largest passenger ship, the Queen Mary 2, sailed majestically into Sydney Harbour at dawn.

As the sun rose over Sydney, the massive vessel manoeuvred its way into a berth at the Garden Island naval base, escorted by a tugboat firing water cannons high into the air.

The QM2, on its first visit to Sydney, was surrounded by a flotilla of craft ranging from yachts to kayaks, and shadowed by helicopters, after it sailed through Sydney heads at 5.45am (AEDT).

Huge crowds gathered on the harbour foreshores to watch the $1 billion, 150,000-tonne ship make its way up the harbour before docking at Garden Island at Woolloomooloo at 7am.

Sydneysiders flocking for a vantage point to see the liner arrive blocked main arterial roads into the city, as well as the Harbour Bridge and the Anzac Bridge, causing long traffic delays.

Those who couldn't see it may well have heard it - with the QM2 giving three loud blasts of its fog horn as it neared its berth.

Towering above the harbour, and with passengers lining its decks, the grand liner took centre-stage in front of the Harbour Bridge before manoeuvering into a berth normally reserved for naval vessels.

The 23-storey-tall ship is too tall to sail under the Sydney Harbour Bridge and too long to berth at Circular Quay, where ocean liners usually dock.

Among the best vantage points for spectators were Mrs Macquarie's Chair and the Sydney Opera House, where onlookers marvelled at the dimensions of the vessel.

"Far out mate, look at the size of that bloody boat," a ranger said as he arrived at work at the Royal Botanic Gardens.

As they tried to get a glimpse of the huge liner, motorists were caught in traffic snarls around the city and there was gridlock on the Sydney Harbour Bridge.

The QM2 sails from Sydney on Tuesday, when it will rendezvous with its sister ship, the Queen Elizabeth 2, as it arrives in Sydney.

It will be their first rendezvous in Sydney - their only joint port of call on this journey - after their predecessors, the Queen Mary and the Queen Elizabeth, visited as troop carriers in 1941 during World War II.

The two modern vessels began their world voyages together in Florida's Fort Lauderdale on January 11 this year.

The ships are scheduled to pass at 7pm (AEDT) on Tuesday night, followed by a 10-minute fireworks display at 8.40pm, accompanied by cannons firing from Fort Denison.

There are about 2,600 guests on board the QM2, 500 of whom are paying between $28,000 and $250,000 each to enjoy its maiden round-the-world voyage.

With 1,600 leaving the ship in Sydney, QM2 owner Cunard estimates the stopovers will inject more than $1 million into the local economy.

The three-year-old QM2 will leave Sydney for Hong Kong at 11pm (AEDT) on Tuesday night, while the QE2 will leave for Brisbane and Cairns on Thursday night.