The crew member's family and friends were joined by emergency services representatives for the ceremony
Hundreds of people have attended a mass in Mayo to remember the victims of Rescue 116.
It is one year to the day since the Irish Coast Guard chopper crashed off Blackrock Island with the deaths of Dara Fitzpatrick, Mark Duffy, Paul Ormsby and Ciarán Smith.
The crewmember’s family and friends were joined by members of the coast guard, Irish Navy, Gardaí and RNLI for today’s service.
Fr Kevin Hegarty spoke about the sense of loss since the tragedy:
The grief is acute for all the families,” he said.
“But especially so for the families of Paul Ormsby and Ciarán Smith - so far, you haven’t recovered the remains of your loved one.
“Your pain is particularly acute because one of the things that helps in a time of bereavement, is to have a place to go to, to pray and reflect.”
Speaking from his St Patrick’s Day tour to the US, the Taoiseach Leo Varadkar said the tragedy remains very much on his mind.
“I am a former Minister for Transport so I know the Coast Guard well,” he said.
“I met Captain Dara Fitzpatrick during my role as a minister and I am conscious at this stage that there are families who are still grieving.
“And of course, there are families who still that do not yet have the remains of their loved ones.
“My thoughts are very much with them and with the Coast Guard at this time.”
The mass was followed by an ocean ceremony that saw the Navy’s LÉ Niamh and the Irish Lights Vessel the Granuaile carrying five wreaths toward the island.
There was one wreath for each crewmember and another for Coast Guard volunteer Caitriona Lucas who died in the line of duty in September 2016.
They were laid close to the Blackrock Island crash site.
It was 12:46am on the 14th of March 2017 when the helicopter came down off the North Mayo Coast.
The bodies of Captain Dara Fitzpatrick and Captain Mark Duffy were recovered in the days following the crash.
However, despite a 42-day search, their colleagues Paul Ormsby and Ciarán Smith remain lost at sea.
2 brave souls were brought home, 2 remain lost to the sea, but all 4 will be forever remembered for the sacrifice they made. Our thoughts today are with the families, friends and colleagues of Dara, Mark, Paul and Ciarán.— Irish Coast Guard (@IrishCoastGuard) March 14, 2018
Go Mairidís Beo#Rescue116 pic.twitter.com/gZSQrOC8bn
Gerard O’Flynn, Search and Rescue Operations Manager with the Irish Coast Guard, said the crash was particularly shocking as it came less than a year after another Coast Guard tragedy - the death of volunteer Caitriona Lucas during an operation off the Clare coast in September 2016.
Gerard explained: "It's your worst nightmare in terms of the job that you do.
"Losing four professional colleagues so soon after we'd lost a volunteer, Catriona Lucas, was a terrible shock - that memory is still very alive, and coming up to the first anniversary brings it all back for everybody."
Local Superintendent Tony Healy, meanwhile, said the Rescue 116 tragedy had a huge impact on the community.
He observed: "They felt it very much as a personal loss - as if it was one of their own families, or one of their own friends, that had been lost at sea.
"You can really see that in the huge, mammoth effort over the long duration of [...] the search - they were as resilient at the start as they were at the end."
Family & friends of those killed in #Rescue116 crash will gather for a vigil tonight to mark one year since the chopper went down off the Mayo coast. This is the view from inside Blacksod lighthouse pic.twitter.com/buFlMD71Qj— Paul Quinn (@pdquinn7) March 13, 2018
Reporting from Paul Quinn in Blacksod