One of the two P&O Ferries vessels which was being held for inspection has been cleared to sail, as the company attempts to resume normal operations.
The Maritime and Coastguard Agency (MCA) said the Norbay has been cleared while the European Highlander is still under inspection.
The ships were being inspected while the company attempts to resume normal operations after sacking nearly 800 seafarers.
A spokesperson for the MCA said a vessel called the Spirit of Britain is now also under reinspection.
They said: “Our surveyors have completed the inspection of the Norbay and it has been cleared to sail.
“The inspection of the European Highlander which began yesterday is ongoing.
“A team of surveyors is now on board the Spirit of Britain carrying out the reinspection at the request of P&O Ferries.
“There are no further inspections of P&O Ferries at the moment.”
European Highlander normally operates between Larne in Northern Ireland and Cairnryan in Scotland, while Norbay serves the Liverpool-Dublin route.
A total of eight P&O Ferries vessels will be examined by the MCA through the Port State Control regime.
Safety fears were raised after P&O Ferries replaced nearly 800 seafarers with cheaper agency staff on March 17.
The firm suspended most of its sailings but reportedly only expected the disruption to last up to 10 days.