The navy is under pressure to share Garden Island with cruise ships on a regular basis. When Cunard's flagship enters the Heads at 5am its 2450 passengers are expected to begin a $2 million spending frenzy.

Sydneysiders have been warned to expect traffic delays and urged to use public transport. Special event clearways will be in place at vantage points.

While few expect the huge crowds and traffic chaos that greeted the luxury liner's inaugural visit in 2007, the focus is on what is being dubbed "Super Sunday" when four luxury cruise ships will be in the harbour. Two will be anchored in the harbour because both the Overseas Passenger Terminal and Wharf 8 in Darling Harbour will be occupied. With Wharf 8 earmarked for a five-year closure while the Hungry Mile is redeveloped, the cruise industry is concerned the NSW Government is failing to come up with a long-term infrastructure plan.

Carnival Australia's chief executive, Ann Sherry, said it was time for the navy to share Garden Island with the cruise industry - worth $1 billion a year.

"Many of the new superliners are too big to fit under the Harbour Bridge. And even the Overseas Passenger Terminal has difficulties because of the size of the terminal and the difficulty large vehicles have moving in and out of The Rocks to reprovision the ship," she said.

The navy has turned down a request to allow the Aurora to dock there on Sunday, citing operational requirements.

Instead Aurora will first moor at Point Piper buoy, before moving that night to the Overseas Passenger Terminal, when Crystal Cruises' Crystal Serenity moves out. Meanwhile, Royal Caribbean's Millennium will be moored at Athol buoy from Saturday to Monday.

The Minister for Ports and Waterways, Joe Tripodi, did not rule out more cruise ships using Garden Island.

A navy spokesman, however, said that there was no spare capacity at Garden Island to establish a dedicated cruise ship facility. The industrial nature of the precinct was incompatible with cruise ship requirements.

Passengers who arrive today will be taken on buses to Wharf 8 for processing of passports.