Southampton will witness a rare maritime meeting today when the world's two most famous liners greet each other.

Queen Mary 2, the biggest passenger vessel ever built, will sail past her older Cunarder Queen Elizabeth 2, signalling the start of the 2005 programme of Southamp-ton-based voyages for both liners.

Crowds are expected to gather on the city's waterfront and a flotilla of yachts and boats is due to follow in the wake of the 151,400-ton megaliner QM2 as she sails from the Mayflower terminal and salutes QE2 in an exchange of blasts from both ships' whistles that will be heard across the city.

Unusually QM2 - the largest, longest, widest, tallest and most expensive passenger ship ever built - will be alongside 106 berth in the Western Docks as QE2, which later this year celebrates the 36th anniversary of her maiden voyage from Southampton, will be moored at the normal Cunard position at 38/9 berth in the Eastern Docks.

It will be the first call to Southampton by the two liners this year after QM2 completes her winter season in the Caribbean and QE2 comes to the end of her 23rd annual world cruise.

The high spot of the day will take place soon after 5pm, when QM2 moves out into the port's main channel to sail close by QE2.

Cunard spokesman Michael Gallagher said: "We hope as many people as possible will be lining the waterfront or on the other side of Southampton Water.''

QM2 will be making her way out towards the open sea for the first of her westbound crossings from Southampton to New York this year, while QE2 is due to sail from the Eastern Docks at 5.45pm, beginning a 13-night cruise that will take the 70,327-ton liner to Madeira, the Canary Islands, Spain, Gibraltar and Portugal.