Prince William and Duchess Catherine will go head-to-head in a sailing regatta next month as they skipper rival boats.
The royals - who have children George, six, Charlotte, four and Louis, 15, months, together - will co-host the inaugural regatta The King's Cup on the Isle of Wight on August 9 and will each skipper a boat as they compete against each other at the event.
An announcement on the Royals.uk website states: "The event will see The Duke and Duchess go head to head as skippers of individual sailing boats, in an eight boat regatta race. The winning team will be awarded The King's Cup, a historic trophy first presented by King George V at Cowes' Royal Yacht Squadron in 1920.
"Their Royal Highnesses hope that The King's Cup will become an annual event, bringing greater awareness to the wider benefits of sport, whist also raising support and funds for the causes that The Duke and Duchess support."
The regatta is being help in support of the couple's charitable causes and each boat taking part will represent one of eight charities supported by Prince William and Duchess Catherine, both 37.
A message on The King's Cup website states: "The eight boats taking part in The King's Cup will each represent one of the charities that are being supported this year by Their Royal Highnesses. These include Child Bereavement UK, Centrepoint, London's Air Ambulance Charity 30th Anniversary Campaign, and Tusk - four causes of which The Duke is Patron.
The Duchess will support four of her patronages: Action on Addiction, Place2Be, the Anna Freud National Centre for Children and Families, and The Royal Foundation in connection with Her Royal Highness's longstanding work on Early Years.
"The Duke and Duchess are strong advocates for sport, and have undertaken work both in the UK and overseas to highlight the positive impact that sport can have on the individual and within local communities. The Duchess in particular champions how the benefits of sport, nature and the outdoors can impact childhood development, and lead to improved physical and mental wellbeing for all.
Their Royal Highnesses hope that The King's Cup will become an annual event, bringing greater awareness to the wider benefits of sport, whilst also raising support and funds for the causes that The Duke and Duchess support."