A school of dolphins triggered a sea rescue operation involving an RNLI lifeboat when they collided with a yacht off the Co Mayo coast.
Shona, a 29-footer with two crewmen on board, could not steer because of a damaged rudder after the unusual incident off Achill Head at about 4.30pm on Thursday. The crew told the lifeboat's volunteer crews that their vessel had been surrounded by a number of dolphins and it appeared one or more of them had struck the rudder, damaging it.
Tom Honeyman, operations manager for the Achill lifeboat, said in his experience such an incident involving dolphins was very unusual. and was "purely an accident".
"There were a lot of them swimming around at the time. The men on the yacht were enjoying watching the dolphins until they got a big bump and their rudder was damaged".
The incident has attracted interest from social media.
Mr Honeyman posted details on Facebook. Up to midday yesterday, some 1,100 comments had been posted on the site.