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

Harry Richards and Charlie Harbord attempt to row the length of the River Thames (346km) from their living room to raise money for the NHS, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 7, 2020. REUTERS/Peter Nicholls

Harry Richards and Charlie Harbord attempt to row the length of the River Thames (346km) from their living room to raise money for the NHS, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 7, 2020. REUTERS/Peter Nicholls

Harry Richards and Charlie Harbord attempt to row the length of the River Thames (346km) from their living room to raise money for the NHS, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 7, 2020. REUTERS/Peter Nicholls

Harry Richards and Charlie Harbord attempt to row the length of the River Thames (346km) from their living room to raise money for the NHS, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 7, 2020. REUTERS/Peter Nicholls

A man jogs by the River Thames in London, following the outbreak of the coronavirus disease (COVID-19), London, Britain, May 6, 2020. REUTERS/Henry Nicholls

A person wearing a head scarf and gloves walks along a footpath beside the River Thames in Dartford, following the outbreak of the coronavirus disease (COVID-19), Dartford, Britain, May 2, 2020. REUTERS/Peter Cziborra TPX IMAGES OF THE DAY

People walk along a footpath beside the River Thames as the Navigator Terminals Thames is seen in the background, following the outbreak of the coronavirus disease (COVID-19), Dartford, Britain, May 2, 2020. REUTERS/Peter Cziborra

A rainbow is seen over the Thames Barrier on the River Thames while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 30, 2020. REUTERS/Steven Watt TPX IMAGES OF THE DAY

A Canada goose walks along the bed of the River Thames during low tide in East London, Britain, April 27, 2020. REUTERS/Steven Watt

People relax on a pier in the River Thames in Silvertown following the outbreak of the coronavirus disease (COVID-19), London, Britain, April 26, 2020. REUTERS/Steven Watt

A man feeds a duck at the banks of the River Thames, as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, April 24, 2020. REUTERS/Hannah Mckay TPX IMAGES OF THE DAY

A man wearing a protective face mask is seen cycling beside the River Thames in Woolwich as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 23, 2020. REUTERS/Steven Watt

A man wearing a protective face mask is seen beside the River Thames in Woolwich as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 23, 2020. REUTERS/Steven Watt

A woman is seen with her face covered as she walks beside the River Thames in Woolwich as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 23, 2020. REUTERS/Steven Watt

A man looks across the River Thames at sunset on Earth Day in London, Britain, April 22, 2020. REUTERS/Kevin Coombs

People walk by the River Thames with a child wearing protective face masks in Silvertown, East London as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, April 21, 2020. REUTERS/Steven Watt

The Houses of Parliament and Big Ben are seen from across the River Thames ahead of Parliament reopening while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 21, 2020. REUTERS/Peter Nicholls

The Houses of Parliament and Big Ben are seen by Westminster bridge from across the River Thames ahead of Parliament reopening while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 21, 2020. REUTERS/Peter Nicholls

The Houses of Parliament and Big Ben are seen by the silhouette of a woman jogging from across the River Thames ahead of Parliament reopening while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 21, 2020. REUTERS/Peter Nicholls

The Houses of Parliament and Big Ben are seen by the silhouette of a man from across the River Thames ahead of Parliament reopening while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 21, 2020. REUTERS/Peter Nicholls

The Houses of Parliament are seen from across the River Thames ahead of Parliament reopening while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 21, 2020. REUTERS/Peter Nicholls

The city of London financial district and the river Thames are seen in early morning, as the spread of coronavirus disease (COVID-19) continues in London, Britain, April 19 2020. REUTERS/John Sibley

The city of London financial district and the river Thames are seen in early morning, as the spread of coronavirus disease (COVID-19) continues in London, Britain, April 19 2020. REUTERS/John Sibley TPX IMAGES OF THE DAY

A river police boat is seen approaching the Thames Barrier as the spread of coronavirus disease (COVID-19) continues in London, Britain, April 15, 2020. REUTERS/Steven Watt

A woman is seen walking her dog while a man walks past beside the River Thames as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 11, 2020. REUTERS/Steven Watt

A model figure holding a placard in support of British health workers is seen on a house boat on the River Thames in London as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 11, 2020. REUTERS/Toby Melville

A model figure holding a placard in support of British health workers is seen on a house boat on the River Thames in London as the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 11, 2020. REUTERS/Toby Melville

People spend time on the banks of the river Thames, as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, April 7, 2020. REUTERS/Marika Kochiashvili

A general view east along the River Thames at sunset in London while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 7, 2020. REUTERS/Dylan Martinez

A general view east along the River Thames at sunset in London while the spread of the coronavirus disease (COVID-19) continues, London, Britain, April 7, 2020. REUTERS/Dylan Martinez

A person walks on Albert bridge over the River Thames as the spread of the coronavirus disease (COVID-19) continues, London, Britain, March 29, 2020. REUTERS/Dylan Martinez

A woman walks opposite the Houses of Parliament, by the River Thames, as the spread of coronavirus disease (COVID-19) continues. London, Britain, March 25, 2020. REUTERS/Hannah Mckay

Men walk by the River Thames near the Thames Barrier as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

A woman relaxes on a pier in the River Thames near the Thames Barrier as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

A man jogs on a pier in the River Thames near the Thames Barrier as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

General view as a man looks out on the River Thames and the Thames Barrier as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

A woman sits on a balcony by the River Thames near the Thames Barrier as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

People on their balconies by the River Thames near the Thames Barrier as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

General view as a man sits on a pier on the River Thames near the Thames Barrier as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

A man walks by the River Thames, as the spread of the coronavirus disease (COVID-19) continues, London, Britain, March 24, 2020. REUTERS/Hannah McKay

People jog wearing protective face masks by the River Thames, as the spread of the coronavirus disease (COVID-19) continues, London, Britain, March 24, 2020. REUTERS/Hannah McKay

Men during a boxing practice session on a pier by the river Thames near Thames Barrier Park in Silvertown as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 24, 2020. REUTERS/Steven Watt

A hot dog carvan sits on the South Bank of the River Thames as the number of coronavirus disease (COVID-19) cases grow around the world in London, Britain, March 22, 2020. REUTERS/Kevin Coombs

A woman rides a bike along the South Bank of the River Thames as the number of coronavirus disease (COVID-19) cases grow around the world in London, Britain, March 22, 2020. REUTERS/Kevin Coombs

A woman looks out across the River Thames towards the financial district as the number of coronavirus disease (COVID-19) cases grow around the world in London, Britain, March 22, 2020. REUTERS/Kevin Coombs

People are seen relaxing along the waterfront beside the River Thames, as the number of coronavirus disease cases (COVID-19) grow around the world, Richmond, south west London, Britain, March 21, 2020. REUTERS/Toby Melville

People are seen relaxing along the waterfront beside the River Thames, as the number of coronavirus disease cases (COVID-19) grow around the world, Richmond, south west London, Britain, March 21, 2020. REUTERS/Toby Melville

People travel on a River Cruise boat on the River Thames as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 18, 2020. REUTERS/John Sibley

People travel on a River Cruise boat on the River Thames as the spread of the coronavirus disease (COVID-19) continues, in London, Britain, March 18, 2020. REUTERS/John Sibley

People walk by the River Thames in Windsor as the number of coronavirus cases grow around the world, in Windsor, Britain, March 17, 2020. REUTERS/Paul Childs

People travel on a boat on the River Thames, as the number of Coronavirus cases grow around the world, in London, Britain, March 17, 2020. REUTERS/Hannah McKay