The UK Royal Navy's second Queen Elizabeth-class aircraft carrier's 680tn Forward Island section, has set sail from BAE Systems to Rosyth.
BAE Systems started construction of this section in December 2013 at its facility in Govan.
The Forward Island, also known as upper block 07, contains the bridge and approximately 100 vital mission systems compartments for the HMS Prince of Wales.
BAE Systems Naval Ships managing director Mick Ord said: "This is a fantastic milestone for HMS Prince of Wales as its Forward Island is delivered ahead of schedule and to an exceptional standard of engineering.
"It's a proud day for everyone on the Queen Elizabeth-class aircraft carrier programme and an important reminder of their tremendous dedication and skill in naval engineering."
This section of the aircraft carrier has up to two metres tall deck-to-deck windows, which will ensure a level of visibility far beyond previous aircraft carriers.
In addition, it is designed to withstand a significant impact, such as a helicopter's spinning rotor blade, BAE stated.
The 65,000tn Queen Elizabeth-class aircraft carriers are the first vessels to use an innovative twin island design.
The Aft Island of the vessel operates as an airport control tower to co-ordinate aircraft movements.
However, both the islands are designed with the ability to incorporate the other's role in an emergency.
Construction of the ship is scheduled for completion in July 2016. The Prince of Wales will the begin sea trials in January 2019, followed by acceptance in August of the same year.
The first aircraft carrier, HMS Queen Elizabeth, is preparing for scheduled sea trials in 2016.
Delivered by the Aircraft Carrier Alliance, a joint initiative by BAE Systems, Thales UK, Babcock and the UK Ministry of Defence, both aircraft carriers will represent Britain's defence capability for the 21st century.
Image: The Forward Island will be the main hub of HMS Prince Of Wales. Photo: courtesy of BAE Systems.