Exasperated George Clooney, 61, grimaces as he waves down boats motoring into shot

There are few film stars more coolly charming than the imperturbable George Clooney.

The actor was left quite unruffled, for instance, when his 2016 wedding in Venice was crashed by a flotilla of paparazzi and hundreds of tourists.

However, in Henley, Oxfordshire, this week, it was a different story.

Clooney, 61, grimaced and yelled his way through a trying afternoon of directing a movie about an Olympic gold medal-winning rowing team.

The problem which was so taxing the star was river users, holiday-makers and rubberneckers drifting into his shot – despite an arrangement with river authorities. This had the effect of somewhat ruining the 1930s period shots he was trying the capture.

George Clooney, 61, boiled over as he directed the period blockbuster The Boys in the Boat about the 1936 American Olympic gold-medal-winning rowing team on the Thames at Henley

The problem which was so taxing the star was river users, holiday-makers and rubberneckers drifting into his shot – despite an arrangement with river authorities

A source on the set said: ‘[George] was shouting ‘Cut’, throwing his arms up in the air, waving his arms above his head, pointing at the leisure cruiser powering by the set. Making the cutting gesture across his throat.’

Clooney is directing a film called The Boys In The Boat about the 1936 Washington State University rowing team, made up of the sons of farmers and boatbuilders, which beat Ivy League rivals to go to the Olympics and then take on the world, watched by Adolf Hitler. 

The Thames at Henley is standing in for Seattle, with Clooney enjoying the luxury of working just a hop and a skip from the £12million home in Sonning, Berkshire, which he shares with his British lawyer wife Amal and their twins.

A source on the set said: ‘[George] was shouting ‘Cut’, throwing his arms up in the air, waving his arms above his head, pointing at the leisure cruiser powering by the set. Making the cutting gesture across his throat’

Clooney is directing a film called The Boys In The Boat about the 1936 Washington State University rowing team, made up of the sons of farmers and boatbuilders, which beat Ivy League rivals to go to the Olympics and then take on the world, watched by Adolf Hitler

River traffic had been closed at intervals on the say-so of the Environment Agency, allowing Clooney 45 minutes at a time to work. During the last week, he was trying to capture a complicated scene showing two teams racing up the river with camera boats behind, and a celebrating crowd in period costume on a barge.

More than once, his shot was ruined by a leisure boat pottering into view.

A source on set said: ‘We have a flowing river, with the very large film set blocking one entire half of it, then two way traffic on the other half of it, going up and down at intervals – like a traffic light system. The weather was really hot on Tuesday meaning there were an awful lot of tourists and locals taking their boats out.

The film is based on a book by Daniel James Brown and stars British actor Callum Turner

‘And of course, once word of filming got out, everyone on the water went to see what was going on.

‘Throughout the day it was 45 minutes of filming, then 45 minutes off. The 45 minutes off was to clear the river traffic building up.

‘There were a couple of slip-ups and boats just didn’t stop when they were supposed to.’

The film is based on a book by Daniel James Brown and stars British actor Callum Turner.