The team hunting for the Coast Guard helicopter missing since last Tuesday have mapped out where they believe the black box lies.
Three of the four crew members are still missing after the aircraft came down off the coast of Mayo.
At the weekend rescue workers provided a guard of honour at the funeral of the helicopter's pilot, Captain Dara Fitzpatrick.
President Michael D Higgins, Taoiseach Enda Kenny, Transport Minister Shane Ross and Fianna Fáil leader Micheál Martin were all in attendance.
Captain Dara Fitzpatrick | File photo
Prayers were said for Captain Fitzpatrick's fellow crew members who are still missing off the Mayo coast.
The Coast Guard's Declan Geoghegan says significant progress was made in yesterday's search operation off Blacksod Bay.
"They've completed the scanning operation and they've mapped the area, so they're now satisfied that they have an in-depth knowledge of the sub-surface and the area that they have to manoeuvre in in relation to carrying out the operation.
"At the moment, the forecast doesn't look great - and I'm mainly talking about swell in that area.
"So if that was to abate in the afternoon or maybe going into Tuesday, it would clear the decks for us in order to get in there with the naval unit and the Granuaile".
