Ciaran Brown (44) was in Lanzarote on his first foreign break since a son was killed in a car crash three years ago.
He apparently got into difficulties while swimming and was pulled unconscious from the sea in front of his wife Celine and sons Ciaran jnr and Eoin.
Friends today paid tribute to Ciaran who lost his son Michael in a car crash in December 2009.
"The family are still only dealing with Michael's death in a car crash," one neighbour in Ballyfermot said.
"This was their first holiday abroad since he was killed."
It’s understood the family had been due to return home from Lanzarote to Dublin today.
Locals on Kylemore Drive in Ballyfermot were today in shock after hearing of Ciaran's death.
“It is a terrible blow to them, it's a blow to us all,” said one neighbour.
“They went away for Christmas and the new year and we think they were due back today.”
The man said he had believed Ciaran was a strong swimmer.
“Nobody knows what happened. We're just waiting for word and for the rest of the family to arrive home,” he said.
One Lanzarote local said red flags were flying on the beach at the time of the tragedy, and said that the sea was “like hell”.
Volunteer ambulance workers tried to save Ciaran as his family went for help. The rescue efforts were aided by two ambulances, the local police and the Civil Guard.
Paramedics are understood to have spend 40 minutes trying to revive Ciaran.
“The waters were extremely dangerous at the time, which is why the red flag was flying,” said a spokesperson for Emerlan, the island’s volunteer emergency service.
“Our volunteers did their best to save his life while waiting for the ambulance service to arrive.”
The emergency services in the Canary Islands said: “We received a call telling us a man had been pulled from the sea. The team from Emerlan found him in cardiac arrest and tried to reanimate him.
“Our paramedics took over when they arrived in two ambulances but they had no success and pronounced him dead,” they added.
One local, writing in a local newspaper website, reported: “The sea was like hell, so crazy.”
Tributes to Ciaran have been posted on his son’s Facebook page. “Sorry to hear the news pal. Head up and thoughts and prayers are with you and your family,” wrote one person.
Another friend said: “I’ve no words to say, other than that I’m shocked to hear the news.
“He was a legend but mostly a gentleman.”
A spokesperson for the Department of Foreign Affairs said they had not been in touch yet with the Brown family.
Five years ago Tallaght man Keith Murphy drowne in a tragic accident in a swimming pool at the same resort.
He had travelled to the holiday island with two friends for a wedding and a holiday.