Update 7pm: The search crew hunting for the wreckage of missing Coast Guard helicopter Rescue 116 are meeting this evening to discuss the next stage of the operation.
The Irish Lights ship, the Granuaile arrived off Blacksod Bay today, fitted with new hi-tech equipment, which has helped the team scan the ocean bed around the suspected crash site.
Heavy swells in recent days had prevented boats from getting near the site where a signal from the black box was detected.
But the Coast Guard's Declan Geoghegan says the weather gave them a break today and they made significant progress; "At the moment it looks like the weather may deteriorate slightly, so we will have to analyse that in the morning.
" This evening's meetings will be to look especially at the information gathered and make a decision based on that for tomorrow's operation."
Earlier: New hi-tech equipment will be used today in the search for Coast Guard helicopter Rescue 116 off the Mayo coast.
Captain Dara Fitzpatrick was laid to rest yesterday while her colleagues Mark Duffy, Paul Ormsby and Ciarán Smith all remain missing.
The Irish Lights ship, the Granuaile has spent the last two days being fitted out in Galway to assist in the search, as rescuers try to take advantage of a weather 'window' later this afternoon.
Poor weather around Blacksod Bay in recent days has prevented boats from getting near the site where a signal from the black box was detected.
The Coast Guard's Declan Geoghegan says there is a massive amount of organisation behind today's operation.
He said: "It's a combination of three agencies, the Irish Lights, the Navy Marine Institute and the Coast Guard working together in terms sharing equipment.
"So there will be sonar equipment and the diving equipment and the back-up in terms of a recompression chamber and generators."
He said more specialist equipment will be used as part of today's efforts.
Mr Geoghegan said: "They're submersibles, thay can go underwater, there is a camera feed to the surface and they can light up an area.
"They can also do certain mechanical operations like attaching cables for lifting equipment and they use a picture of what's beneath the surface."