Investigators have found wreckage from Rescue 116 at Black Rock lighthouse but insist there is no evidence of "impact marks" at the site.
Members of the Air Accident Investigation Unit and their UK colleagues were airlifted onto the island to carry out searches in difficult conditions yesterday.
Investigators trawled the island of Black Rock, located 12km off the west coast, near where the helicopter's 'black box' signal was located.
While pieces of wreckage were discovered at the site, Chief Inspector of unit Jurgen Whyte insisted last night there was no sign of any collision on the lighthouse or in the area surrounding it.
Mr Whyte told RTÉ's Primetime that there has been "no impact marks of significance" discovered and "no marks on the lighthouse".
He said that investigators are eager to get to the main wreckage of the helicopter as that will provide more concrete answers to what happened to Rescue 116.
Divers are now expected to wait until Sunday to carry out a search for the wreckage of Rescue 116 and its three missing crew members.
Meanwhile, funeral details were announced for Captain Dara Fitzpatrick (45), who was recovered from the sea but later pronounced dead.
Pilot Mark Duffy and winchmen Ciaran Smith and Paul Ormsby have still not been located after their helicopter Rescue 116 lost communication shortly before 1am on Tuesday.
Mark Duffy's wife Hermione used Facebook to say she has been "overwhelmed by the love and compassion expressed".
She wrote: "Thank you for the huge outpouring for my beloved Mark, my hero, my soulmate, my right hand but we are both ciotogs, my babies daddy.
"Our hero. I am overwhelmed by the love and compassion being expressed.
"Truly thank you, our children will be so comforted by everything."
A relative of Mark Duffy also paid tribute to the heroic Coast Guard pilot.
Ben Ronayne said: "I woke up early on Tuesday morning, turned on the radio and found out what happened, hopped in the car and came straight up here. I heard the news on the radio. It's disbelief. None of us have been able to get over it yet, it's still a shock. It's not real. It doesn't seem real at all," he said.
"Mark was a fantastic guy. He just had a persona about him. He was an absolute fantastic father and brilliant husband to my cousin.
"He did everything for his kids. As much he could to help, he was just a fantastic man. The waiting is the biggest problem now. The families have been so well looked after up here.
"The wait is just the hardest thing," Mr Ronayne added.
The Duffy family live in Blackrock, Co Louth, where a candlelit vigil will take place at the Sundial at 8pm tonight.
Capt Fitzpatrick, who along with the three missing men would have saved the lives of dozens of people over her distinguished career, will be laid to rest tomorrow. The mass will take place at 11am in St Patrick's Church, Glencullen followed by a cremation at Mount Jerome, Harold's Cross.
The families of the three missing crew members are continuing to be supported by the multiple agencies involved in the search operation and the local community. The Granuaile vessel was expected to arrive at Black Rock at 5am today where it will carry out an underwater sonar-scan once the weather conditions improve.
Derek Geoghegan, of the Irish Coast Guard, said that a window of good weather was paramount for sonar scanning and a dive to be carried out.
"With the weather window we've established we're going to go straight in with an ROV (Remotely Operated Vehicle) or a naval dive team once we've established where the (black) box is, and hopefully that our colleagues are with that wreckage.
"We identified that window of three to four hours on Sunday."
He said they will need to scan the area for obstacles before they can then begin a detailed search.
"The preparatory work we'll have to do, a lot of that this evening and tomorrow in terms of there'll be a scheduling of the vessels going in; it's about 100m from the rock. When you're working in there with a huge swell then there's obviously a danger to the person we would say," he said.