Royal revellers wait in the rain on the South Bank of the River Thames, London, for the start of the Diamond Jubilee river pageant. Photo: Lewis Whyld/PA Wire

Crowds have been gathering for the Diamond Jubilee Thames river pageant which is set to take place in cold and wet conditions.

Despite the gloomy weather, the river banks in central London have been filling up with crowds.

Pageant Master Adrian Evans was still optimistic about the spectacle.

He said: “There is some rain around, but it has not dampened any spirits.

“We in Britain are experts at not letting the weather spoil our fun. The London Philharmonic Orchestra will be playing Singing In The Rain as they travel down the river, and the crowd can sing along with them.

“We are all set to have one of the most spectacular pieces of river theatre that London, and the world, has ever seen. Excitement is building, and everything is ready.”

The pageant will follow a seven-mile route, with more than 1,000 vessels taking part. It will be one of the largest ever gatherings on the Thames.

The Queen and Duke of Edinburgh will be onboard the lavishly decorated royal barge along with the Prince of Wales, the Duchess of Cornwall, the Duke and Duchess of Cambridge and Prince Harry.

Three determined teenagers arrived at the waterfront by Battersea Bridge at 2am in a downpour, setting up a tent and gazebo so they could camp out to secure a prime spot.

They even managed to rig up some bunting as the heavens opened.

Alex Callejon, 16, from Chelsea, said: “We were already drenched after playing football so the rain didn’t make that much difference to us.”

Finn Midgat, 15, his classmate at the French Lycee in South Kensington, added: “We were really worried it would be packed so we wanted to get a spot, it’s a once in a lifetime opportunity.”

Jose Torno, 15, from Madrid, said the group were surprisingly warm in the tent, despite the cold weather.

“With three of us in here it was hotter than we thought. We are doing okay so far,” he said.

Karen Chen, 32 and David Ip, 31, from Streatham, south London, said the rain had not put them off coming to the river early to get a spot.

“We got here just after 7.30, it would have been earlier if we thought we would have more competition. The rain actually works to our advantage,” Ms Chen said.

She added: “Today is a spectacular event, nothing would have stopped us from coming to see the boats. We are so excited about all the variety. It will only happen once in our lifetime and we will be here until the very end.”

Matt Dobson, senior meteorologist at MeteoGroup, said: “For the all important Jubilee Thames Pageant today, the skies will be mostly cloudy with occasional rain and drizzle. However, don’t be surprised if the clouds do thin and break from time to time and a few welcome rays of sunshine may even break through.

“A chilly day in London with temperatures of 12C or 13C, potentially rising to 14C or 15C if it brightens up.”