A search of Lough Ree resumed this morning after a mayday message was received yesterday and distress flares were seen in the area.
The mayday call said a boat was sinking on the midlands lake but did not give any further details.
In response to the signals, the Irish Coastguard Service began a search, which is being led by the Lough Ree sub-aqua unit and the Garda Water Unit are leading the search.
A Garda spokesman said so far the search was concentrated on the area around Quakers Island, close to Newtowncashel, Co Longford, where the flares had been reported. Nothing has been found.