Three members of the missing crew from Rescue 116 have been named locally as Mark Duffy, Ciarán Smith and Paul Ormsby .
The Coast Guard members are all experienced crew members.
Mark Duffy is from Co Louth and Mr Smith is originally from north county Dublin.
Father of two Mark Duffy joined the coastguards in 2002 while living in Blackrock, Louth with his wife Hermione.
Winchman Ciarán Smith (38), from Oldtown in Dublin, is a father-of-three. He is involved in his local GAA club.
Mr Smith lives in Oldtown, in north county Dublin, along with his wife Martina and their three young daughters.
Most of the locals in the small village know Mr Smith well and revealed he is a dedicated family man.
He is a sports fanatic and is heavily involved in his local Wild Geese GAA club in both football and hurling.
Paul Ormsby is the third crew member who has been named as missing this evening.
The search for the missing crew is continuing in Co Mayo.
Resources from the navy, gardaí and local coast guard units were deployed to the scene today as part of the large scale search.
Captain Dara Fitzpatrick, from Kilternan in Co Dublin, was rescued earlier today in critical condition but later died in hospital.
Captn Fitzpatrick was an extremely experienced pilot who had almost 20 years service with the Coast Guard.
She was a high profile water safety campaigner and often spoke publicly about her love for her challenging job.
She is survived by her two year old son.
Her family have led tributes to her today.
Rescue 116 search update
The main wreckage of Rescue 116 including the black box flight recorders have been discovered close to Blackrock Island off the County Mayo coast.
The wreckage is scattered in water 60 metres from the island and close to 200ft cliffs
The location is 9 nm from the Blacksod Lighthouse refuelling depot that rescue 116 was destined for when all contact was lost early Tuesday morning.
The LÉ Eithne has been appointed the on-scene coordinator for the ongoing search and rescue operation for the three Coast Guard crew members still missing. Naval vessel and divers remain on the scene and the Irish Lights vessel Granuaile which has heavy lifting capabilities is en-route to the area.