Hundreds of mariners are expected to take to the waters today in memory of the Rescue 116 crew who crashed off Mayo earlier this year.
The Coast Guard helicopter went down in March with four people on board - the bodies of two of the crew, Paul Ormsby and Ciaran Smith, have never been recovered since.
Today in a cross-border recognition of the scale of the tragedy, a flotilla of boats will take to Carlingford Lough, which straddles the North and Republic of Ireland.
Organiser Sheila Fitzgerald says she has been overwhelmed by the response from both sides of the border:
"We're having a short memorial service on the water," she said.
"We're laying four wreaths in memory of the four crew members and each boat will lay either a white rose or a red rose on the water as R116 flies by.
"The white roses are a symbol of valour, the red roses are a symbol of love, and red and white roses together mean united.
"So it's to say that we stand united as a mariner community in Carlingford Lough behind the valient heroes who died in March."