The Royal Navy flagship HMS Queen Elizabeth has set sail to take part in a US deployment in place of its sister ship which broke down off the Isle of Wight.

HMS Prince of Wales limped back to Portsmouth Naval Base on Saturday after a coupling on its starboard propeller shaft broke.

The £3 billion aircraft carrier will now need to go into dry dock, probably at Rosyth in Scotland, to undergo repairs.

Families of crew members and well-wishers lined the walls of Portsmouth Harbour and waved Union flags to see HMS Queen Elizabeth off on the Transatlantic trip during which it will be accompanied by submarine-hunting frigate HMS Richmond.

The crew of the carrier were notified last week that they would be sailing to the US, altering previous plans for deployments to the Baltic and Mediterranean this autumn.

The navy has not detailed which of HMS Prince of Wales’s diplomatic engagements and military exercises will be carried out by HMS Queen Elizabeth.

The programme included flight trials with F-35B Lightning jets and port stops in New York, Halifax in Canada, and the Caribbean.

But the Royal Navy has confirmed it will be in New York to host the Atlantic Future Forum – a defence conference aimed at strengthening UK and US bonds.

After the US commitments, HMS Queen Elizabeth will return to Europe to take part in operations in the Baltic and Mediterranean with Nato partners.

A Royal Navy spokesman said: “In the coming months, HMS Queen Elizabeth will be at the heart of a powerful task group made up of thousands of sailors, up to 10 ships, F-35B Lightning jets, helicopter squadrons and Royal Marines Commandos which will operate across Europe this autumn.

“The Royal Navy task force will work closely with allies and partners across Europe – from the Baltic all the way south to the Balkans and Black Sea region – over the coming months.

“The operations are part of galvanised NATO efforts in the face of Russia’s unprovoked invasion of Ukraine to safeguard security, stability and prosperity across Europe.”

HMS Queen Elizabeth’s commanding officer, Captain Ian Feasey, said: “After a period of maintenance it is fantastic for the Fleet Flagship to be under way again to conduct operational activity with allies and partners.”

AB warfare specialist Callum Rotherforth, serving his first deployment aboard HMS Richmond, said: “I’ve never been to the USA so I’m really looking forward to going to New York. I want a picture on top of the Empire State Building. It is so cool to be part of a task group sailing across the Atlantic.”

AB Sophie Profitt, who is also on her first deployment onboard HMS Queen Elizabeth, said: “I feel nervous but massively excited and grateful for the opportunity.

“I am looking forward to getting to know what it’s like on board at sea.”

Shortly after the Prince of Wales, the Nato flagship, set sail on Saturday August 27, a mechanical fault was discovered with the starboard shaft.

The departure of the 65,000-tonne ship had already been delayed from the previous day because of a technical problem but a decision was taken to sail anyway.

The carrier returned to Stokes Bay in Gosport, Hampshire, two days later, travelling at a rate of four knots and accompanied by tugs for the journey to calmer waters.

Navy divers have been inspecting the ship and found that a coupling on the starboard propeller shaft had failed.

Rear Admiral Steve Moorhouse, director of Force Generation, who is responsible for making sure Royal Navy ships are ready to deploy, confirmed on Friday that HMS Queen Elizabeth would take over the US duties.

He said: “Royal Navy divers have inspected the starboard shaft of the ship and the adjacent areas and they have confirmed there is significant damage to the shaft on the propeller and some superficial damage to the rudder but no damage to the rest of the ship.

“Our initial assessment has shown that coupling that joins the final two sections of the shaft has failed.

“Now, this is an extremely unusual fault and we continue to pursue all repair options.”