Two separate search operations are under way for three men missing off the coasts of Clare and Cork.
A boat carrying two fishermen failed to return to port in Quilty, Co Clare this afternoon.
The 26-foot vessel, Lady Eileen, was last seen south of Hag's Head at around 1pm. It was due in port at 5pm.
The Doolin unit of the Coast Guard and the Aran Islands RNLI lifeboat are involved in the search.
Meanwhile, the Shannon-based rescue helicopter was diverted to a search operation after a boat overturned off Cod's Head in Co Cork.
It is understood a man and his teenage son were on board.
The teenager managed to swim ashore and raise the alarm.
The Castletownbere lifeboat was launched at 9.40pm and began a search of the area for the missing man.