Pedestrians view Hammersmith Bridge, the closure of which has caused the annual Oxford versus Cambridge boat race on the River Thames, which passes under the now structurally dangerous Victorian bridge, to be relocated outside of London for the first time since World War Two, London, Britain, November 26, 2020. REUTERS/Toby Melville

A warning sign is seen attached to Hammersmith Bridge, the closure of which has caused the annual Oxford versus Cambridge boat race on the River Thames, which passes under the now structurally dangerous Victorian bridge, to be relocated outside of London for the first time since World War Two, London, Britain, November 26, 2020. REUTERS/Toby Melville

Houseboats are seen moored near to Hammersmith Bridge, the closure of which has caused the annual Oxford versus Cambridge boat race on the River Thames, which passes under the now structurally dangerous Victorian bridge, to be relocated outside of London for the first time since World War Two, London, Britain, November 26, 2020. REUTERS/Toby Melville

Pedestrians view Hammersmith Bridge, the closure of which has caused the annual Oxford versus Cambridge boat race on the River Thames, which passes under the now structurally dangerous Victorian bridge, to be relocated outside of London for the first time since World War Two, London, Britain, November 26, 2020. REUTERS/Toby Melville

A woman feeds birds on the bank of the river Thames with London's financial district seen in the background, amid the coronavirus disease (COVID-19) in London, Britain, November 25, 2020. REUTERS/Simon Dawson

A woman feeds birds on the bank of the river Thames with London's financial district seen in the background, amid the coronavirus disease (COVID-19) in London, Britain, November 25, 2020. REUTERS/Simon Dawson

A woman feeds birds on the bank of the river Thames with London's financial district seen in the background, amid the coronavirus disease (COVID-19) in London, Britain, November 25, 2020. REUTERS/Simon Dawson

A canoeist paddles on the river Thames as a minibus escapes floodwater from the river bursting its banks at high tide in London, Britain, November 17, 2020. REUTERS/Peter Nicholls

A man cycles through floodwater as the river Thames burst its banks at high tide in London, Britain, November 17, 2020. REUTERS/Peter Nicholls

A man cycles through floodwater as the river Thames burst its banks at high tide in London, Britain, November 17, 2020. REUTERS/Peter Nicholls

A cyclist avoids floodwater as the river Thames burst its banks at high tide in London, Britain, November 17, 2020. REUTERS/Peter Nicholls

A man crosses a footbridge over the River Thames, amid the outbreak of the coronavirus disease (COVID-19), on the first day of a newly imposed lockdown, in London, Britain November 5, 2020. REUTERS/Toby Melville

People walk along the south bank of the River Thames, during sunset, in London, Britain, October 22, 2020. REUTERS/Henry Nicholls

An inflatable Borat character promoting movie "Borat Subsequent Moviefilm" is carried along the River Thames from Tower Bridge aboard a barge, in London, Britain October 22, 2020. REUTERS/Peter Nicholls

An inflatable Borat character promoting movie "Borat Subsequent Moviefilm" is carried along the River Thames from Tower Bridge aboard a barge, in London, Britain October 22, 2020. REUTERS/Peter Nicholls

An inflatable Borat character promoting movie "Borat Subsequent Moviefilm" is carried along the River Thames from Tower Bridge aboard a barge, in London, Britain October 22, 2020. REUTERS/Peter Nicholls

An inflatable Borat character promoting movie "Borat Subsequent Moviefilm" is carried along the River Thames from Tower Bridge aboard a barge, in London, Britain October 22, 2020. REUTERS/Peter Nicholls

An inflatable Borat character promoting movie "Borat Subsequent Moviefilm" is carried along the River Thames from Tower Bridge aboard a barge, in London, Britain October 22, 2020. REUTERS/Peter Nicholls

A man feeds birds as he sits on steps next to the River Thames in view of the financial district, as the coronavirus disease (COVID-19) outbreak continues in London, Britain October 18, 2020. REUTERS/Simon Dawson

A man feeds swans on the South Bank of the River Thames, during rainy weather, in London, Britain, October 4, 2020. REUTERS/Henry Nicholls

Two swans swim in the River Thames as the sun rises, in London, Britain, September 15, 2020. REUTERS/Henry Nicholls

A woman makes her way along the River Thames as she enjoys a sunny weather, in London, Britain September 14, 2020. REUTERS/Hannah McKay

A woman makes her way along the River Thames as she enjoys a sunny weather, in London, Britain September 14, 2020. REUTERS/Hannah McKay

People sit on a sightseeing boat on the River Thames, amid the coronavirus disease (COVID-19) outbreak, in London, Britain, August 21, 2020. REUTERS/Henry Nicholls

A bevy of swans swims up the River Thames in London, Britain, August 20, 2020. REUTERS/Henry Nicholls

A teenager jumps from a bridge crossing the river Thames in Weybridge, Britain August 20, 2020. REUTERS/Peter Nicholls

A woman rows in between swans on the river Thames in Weybridge, Britain August 20, 2020. REUTERS/Peter Nicholls

People enjoy the weather in the River Thames, in London, Britain, August 7, 2020. REUTERS/Dylan Martinez

People enjoy the weather in the River Thames, with Canary Wharf financial district in the background, in London, Britain, August 7, 2020. REUTERS/Dylan Martinez

People enjoy the weather in the River Thames, with the City of London in the background, in London, Britain, August 7, 2020. REUTERS/Dylan Martinez

People enjoy the weather in the River Thames, with the City of London in the background, in London, Britain, August 7, 2020. REUTERS/Dylan Martinez

An Uber boat is pictured following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

An Uber boat operates following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

An Uber boat operates following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

An Uber boat operates following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

An Uber boat passes under Westminster bridge with the Houses of Parliament in the background, as it operates following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

An Uber boat operates following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

An Uber boat operates following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

An Uber boat operates following the launch of the new boat service on the River Thames in London, Britain, August 3, 2020. REUTERS/John Sibley

People sit socially distanced in the sunshine on a tourist cruise boat on the River Thames in London, Britain, July 31, 2020. REUTERS/John Sibley

People sit on an inflatable tourist tour boat on the River Thames, in London, Britain, July 31, 2020. REUTERS/John Sibley

People sit in the sunshine on a tourist cruise boat on the River Thames in London, Britain, July 31, 2020. REUTERS/John Sibley

People enjoy themselves along the edge of the River Thames in Richmond, following the coronavirus disease (COVID-19) outbreak in London, Britain, July 5, 2020. REUTERS/Toby Melville

People enjoy themselves on the River Thames in Richmond, following the coronavirus disease (COVID-19) outbreak in London, Britain, July 5, 2020. REUTERS/Toby Melville

People enjoy themselves along the edge of the River Thames in Richmond, following the coronavirus disease (COVID-19) outbreak in London, Britain, July 5, 2020. REUTERS/Toby Melville

People sit and drink in front of a bar by the Thames River in central London after its reopening following the outbreak of the coronavirus disease (COVID-19) in London, Britain July 4, 2020. REUTERS/Peter Nicholls

People enjoy the hot weather as they sit along the river Thames in London, Britain, June 24, 2020. REUTERS/Hannah McKay

People socialise with alcohol along the River Thames, in London, Britain June 18, 2020. REUTERS/Hannah McKay

A Keep Clear message is seen on the pavement as people enjoy the hot weather on the bank of the River Thames in London, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 31, 2020. REUTERS/Steven Watt

An ice cream van is seen as people enjoy the hot weather on the bank of the River Thames in London, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 31, 2020. REUTERS/Steven Watt

The Shard and the City hall are seen as people enjoy the hot weather on the bank of the River Thames in London, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 31, 2020. REUTERS/Steven Watt

A man is seen relaxing by the RIver Thames in Central London following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 25, 2020. REUTERS/Henry Nicholls

A banner in tribute to the NHS is seen on the River Thames as a boat goes past following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 21, 2020. REUTERS/Steven Watt

People walk along the river thames in the City of London, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 15, 2020. REUTERS/Toby Melville

A rower is reflected as he trains on the River Thames, following the outbreak of the coronavirus disease (COVID-19), in West London, Britain, May 15, 2020. REUTERS/Toby Melville TPX IMAGES OF THE DAY

A rower is reflected on the River Thames as he trains, following the outbreak of the coronavirus disease (COVID-19), in West London, Britain, May 15, 2020. REUTERS/Toby Melville

A man is seen kayaking on the River Thames in East London as restrictions on watersports have been lifted following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 14, 2020. REUTERS/Steven Watt

People wearing protective face masks walk by the River Thames following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 10, 2020. REUTERS/Henry Nicholls

People walk by the River Thames following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 10, 2020. REUTERS/Henry Nicholls

A woman wearing a protective face mask walks with another woman by the river thames following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 10, 2020. REUTERS/Henry Nicholls