The Royal Navy's HMS Queen Elizabeth has left Portsmouth this morning for her first flight trials with British fighter jets in UK waters.
The £3.1 billion aircraft carrier now has three testing points to pass before gaining initial operational capability.
During the flight trials, it is expected British F-35Bs will make their first landings on Queen Elizabeth in UK waters.
The joint Royal Navy and Royal Air Force Lightning Force training squadron, 207 Squadron, will conduct the trials, flying aircraft to and from the decks, day and night from their base at RAF Marham.
Six pilots, from the Navy and RAF, will carry out their aircraft carrier qualification during that time.
The first launch of a British Lightning jet from the carrier in the UK took place in Portsmouth in December.
Last year, HMS Queen Elizabeth spent a few months off the east coast of the United States, undergoing flight trials with F-35s.
He said it was a "real honour" to be taking the aircraft carrier to sea as commanding officer.
When Capt Essenhigh took over from Commodore Steve Moorhouse, it made him the ship's third captain in the space of 10 months.
During the forthcoming trials, F-35B pilots will land their aircraft on to the flight deck of HMS Queen Elizabeth in different conditions, as well as providing further tests for the aircraft carrier's crew.
Lieutenant Commander Richard Turrell, Flight Deck Officer, HMS Queen Elizabeth, said: "This is a fantastic opportunity to further integrate and qualify United Kingdom F-35B pilots, ground crews and aircraft on board HMS Queen Elizabeth in UK waters.
"My team are excited to get to sea and continue the development of our ship to Air Wing partnership throughout 2020 and beyond to deploying with full carrier strike capability in 2021."
Queen Elizabeth is expected to become operational in 2021.
Meanwhile, her sister ship HMS Prince of Wales recently commissioned into the Royal Navy.
The two aircraft carriers are expected to be in service for the next 50 years.
Measuring 280 metres in length and weighing 65,000 tonnes, the two ships could be deployed in a range of roles from providing humanitarian aid or disaster relief to high-intensity warfare.