"This marks a huge milestone for the programme to deliver the nation's flagships.
"Now it is at Rosyth the hard work continues as we begin the massive task of joining it to the sections of HMS Queen Elizabeth already in place."
A complex engineering effort will shortly begin to float the block off the specialist barge and move it into position in the dock.
Once it is in place the dock will be drained and work to start integrating the sections will begin.
The aircraft carriers HMS Queen Elizabeth and HMS Prince of Wales are being delivered by the Aircraft Carrier Alliance, a partnering relationship between BAE Systems, Thales UK, Babcock and the UK Ministry of Defence.