The 11,000 tonne block of HMS Queen Elizabeth was to be slowly moved on to the giant barge, but the operation had to be delayed for 24 hours because of a "technical problem" affecting the ballast system on the giant barge.
However, shipyard bosses said final preparations were under way to ensure the move would be made tomorrow morning.
They insisted the delay would have no impact on its scheduled departure from Govan early next month.
The section had been moved out of a hall at BAE Systems' Govan Shipyard in Glasgow yesterday ready for loading on to a barge for its 600-mile journey to the Fife dockyard next month.
A team of 40 people moved the section, known as Lower Block 04, across reinforced Tarmac in less than three hours using 450 remote controlled transporters.
The 80-metre long and 40m wide section, which houses a hospital, a dental surgery and 242 accommodation berths, will take five days to travel to Rosyth, where it will be joined up with the other parts of the ship that were constructed in Portsmouth.
HMS Queen Elizabeth is due to be completed by 2016, with another aircraft carrier, HMS Prince Of Wales, following later. They could be deployed in active service from 2017.
They are being delivered by the Aircraft Carrier Alliance, a partnership between BAE Systems, Thales UK, Babcock and the Ministry of Defence.
Project director Steven Carroll described it as "the largest and most powerful warship we have ever built for the Royal Navy".