London ( CNN ) -- Dragon boats , a floating belfry and the royal barge are among more than 1,000 vessels preparing to transform London 's River Thames into a spectacular floating tribute to the 60-year reign of Queen Elizabeth II . About 20,000 people will take to the water Sunday for a river pageant -- inspired by regal riverside celebrations of the past -- which is set to be the largest such event on the Thames for hundreds of years . The event is set to be a highlight in a four-day weekend of celebrations for the queen 's diamond jubilee . What 's on during Diamond Jubilee weekend . After gathering upriver in west London , the seven-mile long flotilla will wend its majestic way from Battersea Bridge to Tower Bridge , passing through the heart of Britain 's capital city over the course of several hours . At the front will be about 300 man-powered boats , with thousands of volunteers propelling them downriver , flags and streamers fluttering around them . A barge carrying the eight Royal Jubilee Bells -- the largest of which , at nearly half a ton , is named for the monarch -- will lead the way , its peals of bells to be echoed from church towers along the river . Fashions and treats fit for a queen . Next will come passenger boats , pleasure boats , historic wooden vessels -- the oldest built in 1740 -- and boats carrying members of the armed forces , police and fire services . One of the boats taking part , the Amazon , also took part in the 1897 Diamond Jubilee celebrations for Queen Victoria , Britain 's longest-serving monarch and the only other to reach the landmark 60 years on the throne . The biggest cheer will no doubt come for the present queen , who will be carried aboard a specially converted royal barge , opulently draped in red and gold . Huge numbers of flag-waving spectators are expected to line the banks , despite the forecast for rain . Millions more around the world are likely to watch the spectacle unfold on television . Sailing boats that are too tall to pass under the 14 bridges along the river pageant route will line the river from London Bridge to Wapping , in the east , creating an avenue of sails set against the Tower of London and the city 's financial center . The queen will disembark at Tower Bridge and watch as the remainder of the river pageant passes in a riot of color and noise . More than 14 miles of bunting in the colors of the Union Flag , or the Union Jack as it is commonly referred to , will be strung along the route , pageant organizers say . London 's Metropolitan Police said as many as 6,000 extra officers would be on patrol during jubilee events . The force will deploy more than 20 police boats during the river pageant , as well as carrying out searches on shore with dogs , and using rope climbing teams to inspect the bridges . Police divers will carry out underwater checks of piers and boats . The huge security operation comes as London prepares to host the 2012 Olympic Games , which open in late July . Outside the capital , Britons are expected to gather for thousands of Jubilee-themed street parties and barbecues Sunday . Stores have been filled for weeks with an array of patriotic paraphernalia , from flag-adorned teapots to aprons to picnic sets , to help hosts set the scene for what is billed as a national celebration . The queen , known for her love of horse racing , kicked off the long weekend at Epsom Downs racecourse Saturday , where she attended the Derby , Britain 's most prestigious racing meet , with her husband , the Duke of Edinburgh . Singer Katherine Jenkins performed the national anthem and the King 's Troop Royal Horse Artillery fired a gun salute in the Queen 's honor . The celebrations continue on Monday and Tuesday , which have been declared public holidays to mark the diamond jubilee . An afternoon garden party at Buckingham Palace will be followed Monday evening by a televised pop concert outside the palace grounds . At the end of the concert , the queen will take to the stage to light the `` National Beacon , '' which will be on the Mall . She will use a diamond made from crystal glass , which has been on display at the Tower of London from the beginning of May , to light the flame . More than 4,000 beacons will be then lit in communities throughout the United Kingdom , along with the Commonwealth and UK Overseas Territories . Tuesday will be a day of pomp and ceremony , as the queen attends a service of thanksgiving at St. Paul 's Cathedral , followed after lunch in Westminster by a carriage procession back to Buckingham Palace , where she will appear on the balcony , flanked by members of the royal family .
The queen will be carried aboard a specially designed royal barge , draped in red and white . More than 1,000 boats of all shapes and sizes are taking part in the pageant on the Thames . Large crowds are expected to line the riverbanks as they pass , despite a rainy season . The river pageant is part of three days of celebrations for the Queen 's Diamond Jubilee .