THE former royal yacht Britannia ruled the waves for a final time yesterday as she completed a 560-mile voyage to her retirement home in Scotland.

The water may have been deeper than the crowd who witnessed ''the Grand Old Lady of the Sea'' inching her way into the docks at Leith, but the pomp and ceremony surrounding the arrival ensured a real sense of occasion at the historic port.

Scottish Secretary Donald Dewar and Edinburgh's Lord Provost Eric Milligan were among the welcoming party on the quayside as the vessel, described as ''a symbol of one of the great products of Scottish shipbuilding'', made her entrance before several hundred appreciative onlookers.

Some years ago, on one of her previous visits to Leith, Britannia had to manoeuvre through an armada of trawlers as fishermen protested about new legislation.

This time, there were no such obstacles to the final stages of the vessel's graceful journey up the Firth of Forth.

Work on restoring the decommissioned royal yacht at her permanent home at Leith will begin today at the port's Imperial Dry Dock. In four months' time, the vessel will go on public display at an interim berth.

She will stay there until the millennium and the completion of her long-term home at Ocean Terminal, the planned #75m cruise liner terminal and retail development.

Lord Provost Milligan said of Britannia just moments after she docked on schedule around 10.45am: ''Over the past four decades, you have sailed the whole world, introducing the best of British style and prestige wherever you have gone. We are all certain that you will bring that same style and prestige to your new home.''

He said it was most appropriate that a Scottish-built ship had returned north of the Border to familiar waters and a city proud of its historic royal links.

''Britannia,'' he said, ''you will become a symbol of the revitalisation of the ancient port of Leith.''

Mr Terry Smith, property director of Forth Ports and the man who masterminded its successful bid for Britannia in the face of competition from others, including Glasgow, said it was ''a wonderful day''.

He travelled on the tug which has escorted Britannia over the past four days from Portsmouth and said that, as a Glasgow man who had worked at Clydebank close to its launch site, he had some sympathy for his home city.

The Forth Ports Authority official indicated there had already been worldwide interest in Britannia and one Yorkshire company had already booked 4500 tours of her over a three-month period.

Mr Smith said they were still in discussions with the curators of the Royal Collection and were hopeful art works and furniture housed in Britannia during her working life would be loaned to allow the public to see her as she was when home to the royal family.

He said the vessel would be ''the jewel in the crown'' of the waterside development.