The second of two long-delayed ferries built at the Ferguson Marine shipyard has set off for its builder's sea trials.

The 335ft (102m) long Glen Rosa set sail from Inchgreen quayside in Greenock earlier.

It will undergo tests in the Firth of Clyde, with specialists measuring its handling and propulsion systems.

Glen Rosa's sister vessel, MV Glen Sannox, entered service with CalMac in January 2025 after years of delays.

The current timetable is for Glen Rosa to be handed over in February 2027, after the expected date was put back from the end of this year to allow the ship to be delivered with new redesigned propellers.

Ferguson Marine, which is owned by the Scottish government, said the new blades would address a vibration issue which emerged after its sister vessel Glen Sannox went into service last year.

The dual-fuel ship is currently running on diesel, but its liquefied natural gas (LNG) systems are expected to be commissioned once the new propellers are fitted.

The sea trials will check the ferry's propulsion, power generation, safety, automation and navigation systems, under real sailing conditions.

Andrew Milligan, executive director of technical at Ferguson Marine, said: "Commencing sea trials is a pivotal moment for Glen Rosa and reflects the tremendous hard work and technical skill across our Port Glasgow shipyard.

"These trials allow us to put the ship's integrated systems through their paces at sea, validating months of dockside testing and outfitting."

He added: "Our team remains completely focused on producing quality work and rigorous testing, ensuring we deliver a reliable, robust vessel that will serve island communities for generations to come."

Kevin Hobbs, chief executive of CMAL, which owns the ferries, said: "Builder's sea trials are an important milestone, and we welcome the progress as we near the handover of MV Glen Rosa."

Builder's sea trials are the first in a series of at-sea testing voyages of a ship, which are followed by owner's acceptance trials and a final regulator approval process.

Once delivered, CalMac will also want to conduct its own crew familiarisation and berthing trials before the ship begins carrying passengers.

But construction soon fell behind schedule with the shipyard's then owners and government owned ferries agency CMAL blaming each other for the problems.

The two ships were initially expected to cost £97m the repeated delays and technical challenges have resulted in a succession of large cost increases.

An extra £150m has been required to finish Glen Sannox since Ferguson's was taken into public ownership in 2019, and the latest estimate for completion of Glen Rosa is £197.5m.

These figures are over and above the £83m paid out prior to nationalisation and do not include £45m of written-down government loans to the shipyard.