Yiannis, who had driven with his family from their home in Kallithea, in the southern suburbs of Athens, to their summerhouse in Mati on Monday afternoon, spent hours desperately searching local hospitals for his daughters and their grandparents.
However, hopes of the girls being found alive began to fade when another passenger on the boat came forward to confirm that the children belonged to him.
The death toll from the worst wild fires in Europe this century rose to 88 on Friday night after a woman in her 40's died in hospital. The unnamed woman had been in hospital since Monday.
The Health Ministry said 12 other people remained in hospital with serious injuries.
Forensics experts have faced a difficult task trying to identify the bodies of those who perished.
Greek Prime Minister Alexis Tsipras said on Friday he assumed "political responsibility" for the tragedy.
The government has come in for strong criticism over its response to the disaster despite a €40 million relief fund.
Experts have said that a mix of poor urban planning, including a lack of proper access routes and the construction of too many buildings next to combustible forest areas, contributed to what were Europe's worst wildfires this century.
