There are concerns that a fin whale stranded in Baltimore harbour in west Cork will be unable to return to sea.
The whale, estimated to be 18m long, was first spotted making its way through moorings in the harbour shortly after 8am.
It remains in shallow waters beside the pier after failing to leave the area during mid-afternoon high tide.
A large crowd gathered today to see the mammal, which has also wounded itself on sharp rocks close to the pier.
Kieran Cotter of Baltimore Lifeboat said the chances of the whale surviving were "near nil", as it appeared emaciated and ill.
He said if the whale did die, he anticipated an effort would be made to haul the mammal out to deep sea and sink it there.
Given an adult can grow up to 25m, it is thought this is a young whale.
Boats are being kept away from the whale to ensure it does not become distressed any further.