An operation to lift the wreckage of Coast Guard Rescue Helicopter 116 from the sea bed off Co Mayo has been cancelled this evening due to spring tides.
Another attempt will be made tomorrow morning if weather permits. However conditions are expected to deteriorate over the coming days.
The search for the two missing crew members, Paul Ormsby and Ciaran Smith, has entered its third week.
A search for debris and any trace of the two has been expanded.
Coast Guard and Civil Teams have been joined by a number of RNLI lifeboats in combing sea and shoreline areas stretching from Downpatrick Head to north of Killybegs in Co Donegal.
The Shannon and Sligo-based rescue helicopters are also assisting in the effort.
Books of condolence have been opened at three centres in Co Louth for Captain Mark Duffy and the crew of the Coast Guard Rescue Helicopter 116.
Members of the public can access the books at the County Hall and Town Hall in Dundalk and at the Ardee Library.
The remains of the 51-year-old father-of-two are reposing at his home in Blackrock from 1pm to 7pm tomorrow.
His funeral mass will take place on Thursday at St Oliver Plunkett Church, Blackrock at 11am.
The funeral of Captain Dara Fitzpatrick took place in Dublin earlier this month.
Naval Service divers attached a number of lifting bags to the fixed cabin and rotor assembly area of the aircraft wreckage last evening and this morning.
The bags were connected to a low pressure air hose, which can be operated from the surface, 40m above the helicopter weckage.
For safety reasons, divers have to retreat while the bags are slowly inflated. The operation aims to tilt the helicopter, allowing crews to view the area below the wreckage.
Conditions are monitored by the Marine Institute's 'Holland 1' Remotely Operated Vehicle (ROV).
It streams video of the operation to search commanders in real time.
The ROV is also used to light the process and is in a position to intervene, with a number of grabbers, if any items of interest float away on strong currents.
The operation has been described as the final phase of the search and rescue operation around the wreckage.
A wider area off Blackrock is to be surveyed by underwater cameras and garda divers
In addition, some coastal and air sea searches are being carried out in an area north of the crash site, up to and including Donegal Bay.