Joby Fox fights back tears, his voice breaking, as he recalls reaching out his hand into the darkness towards a refugee struggling in the water off the coast of Greece.
"He kept trailing this bag and I was shouting 'leave the bag, c'mon, c'mon'.
"So he managed to grab the bag about the third time and he trailed it and held it up into his chest.
"And.... it was a wee baby... it wasn't a bag.... it was a wee baby. At that moment I realised these guys are risking everything; everything."
Joby is a musician from Belfast and one of three volunteers from Northern Ireland who feature in the BBC documentary 'True North - The Crossing'.
It tells the extraordinary story of how Joby, his friend, Jude Bennett, an art curator, and Michael Cecil, who normally skippers the Rathlin Island ferry, have helped to save the lives of thousands of refugees.
It follows the trio as they struggle against the elements and the authorities to rescue migrants attempting to cross the Mediterranean Sea between Turkey and Greece.
Almost invariably, the desperate refugees find themselves battling for their lives in ill-equipped, unsuitable craft.
Joby initially tried to help from the shore but he soon came to realise that the way to really make a difference was to take the help to where the need is greatest - on the water.
Jude used her contacts in the art world to persuade an anonymous donor to help them to buy a rigid inflatable boat.
They recruited Michael to pilot it and were joined by two lifeguards from Devon.
The five-strong team then set up a 24/7 search and rescue operation but they have been frustrated by an apparent unwillingness to help on the part of the Greek authorities.
Michael said: "It's always a possibility that the Greek authorities, or maybe European authorities, are trying to make this crossing a little bit more difficult, a little bit more dangerous in the hope that it puts people off attempting it in the first place."
There is frustration, too, with the big charities with Joby claiming they have failed to help as they should have.
"These big, over-bloated so-called humanitarian organisations; they do great work so you can't criticise them, yet when they get it wrong.
"Well, they got it wrong here and people need to know about that. They got it spectacularly wrong and the price that was paid was lives out on that sea".