The Stornoway freight ferry is undergoing repairs after hitting rocks on Friday morning.
The MV Mùirneag has holed a ballast tank and will have a fresh steel plate welded in drydock in Aberdeen.
The £ 3.2 million ship ran aground on a reef while manoeuvring towards her berth in Stornoway harbour around 8 am on Friday.
Though the ship can handle rough seas she is built to carry much more and heavier cargo than is available from Lewis. The lack of weight and twin rudders makes close-quarters manoeuvring tricky in bad weather. It means she often does not sail in adverse conditions only because of the risk of damage to the pier when going astern.
However conditions were good on Friday morning and it is thought a cause of the grounding may be connected with an electrical failure involving the steering gear preventing one of her twin rudders from operating.
The ship which has an underwater draft of 5 metres was stuck on the rocks for half an hour but managed to free herself using her engine and helped by the incoming flood tide.
Stornoway lifeboat stood by the stricken 29-year-old vessel but was not required to take any crew members off.
The MV Mùirneag managed to navigate onto the linkspan under her own power and tied up at the port's number one pier.
The Mùirneag is managed by ASP Glasgow and chartered to Cal Mac for its dedicated nightly freight route between Ullapool and Lewis.
ASP flew a ship superintendent to Stornoway on the next flight to carry out a preliminary investigation.
Divers were sent down to inspect the underwater hull plating and to check her propeller and rudders.
It is understood that they discovered damage which may be a bad dent which requires repair before it worsens. She sailed from Stornoway on Saturday afternoon arriving off Aberdeen early on Sunday morning. She anchored 1.5 miles off the coast and went alongside in Aberdeen harbour at 3.30 pm today (Sun) to await going into drydock around 8 pm tonight.
