President Michael D Higgins was among hundreds of mourners at St Patrick's Church in Dublin for the funeral of Coast Guard Captain Dara Fitzpatrick.
The funeral cortege arrived at the church in Glencullen at 11am and was met by an honour guard from the Coast Guard and other rescue services.
Captain Fitzpatrick died after the Coastguard Rescue 116 helicopter crashed off the Mayo coast on Tuesday.
Captain Fitpatrick's parents, four siblings, her young son Fionn, and other family members accompanied the coffin into the church.
As well as President Higgins, Taoiseach Enda Kenny and Minister for Transport Shane Ross were in attendance, as was Fianna Fáil leader Micheál Martin.
In his homily, Parish Priest Fr Andrew O'Sullivan said St Patrick's church had seen many sad and tragic funerals but few as sad and sorrowful as today's.
He paid tribute to the Fitzpatrick family and said they and the community had lost a loved and valued member.
He said the congregations' thoughts were with Captain Fitzpatrick's three crew members who have yet to be found.
Fr O'Sullivan said the family took comfort from the fact that Dara had lived life to the full.
Mourners heard that as well as being a loving mother, Dara was an avid traveller, cook and animal lover.
Coastguard standard bearers and lone piper pic.twitter.com/ctNZhFYjtv— Damien Tiernan (@damienrte) March 18, 2017
Also present were members of the RNLI, Civil Defence, mountain rescue and many other groups.
The bells ring out at start of funeral mass for Captain Dara Fitzpatrick pic.twitter.com/terkCpqU5L— Damien Tiernan (@damienrte) March 18, 2017
The funeral Mass was followed by cremation at Mount Jerome Crematorium.
Poor weather conditions off the west coast are continuing to hamper the search for three crew members missing from Coast Guard helicopter R116.
Agencies involved in the operation say it may be some time before they can try to access the area where they believe the wreckage of the aircraft is located.