Princes William and Harry have joined soldiers distributing sandbags to protect properties in the flooded village of Datchet.
Wearing Wellington boots and waterproofs, they lugged sandbags alongside members of the Household Cavalry. Datchet is 1.5km from Windsor Castle.
A reporter for The Guardian spotted them helping members of the Household Cavalry load sandbags onto a railway truck.
Prince William asked him to put the notebook down and ''give us a hand".
Also on Friday, Buckingham Palace said the queen was helping farmers in Somerset by contributing feed and bedding from the royal farms at Windsor.
January was the wettest in 250 years in England and Wales. More than 5800 properties have been flooded since early December and huge areas of farmland are under water.
The Met Office said up to 40mm of rain could fall on Friday and the Thames River is expected to reach its highest level in 60 years this weekend.
Seventeen severe flood warnings remain in place in the Thames Valley, Somerset and Gloucestershire, as well as 131 flood warnings across England and Wales.