Over 40 experienced divers are expected in west Cork later this week following an appeal for help in the on-going search for a 20-year-old missing student.
Barry Davis Ryan was one of a group of people walking close to the Beacon when one of them was swept into the sea.
Two others attempted a rescue before all three got into difficulty.
The bodies of 20-year-old Niamh O'Connor and Barry's father, 51-year-old Barry Ryan, were later recovered from the sea.
Their funerals took place over the weekend.
John Kearney of West Cork Underwater Search and Rescue said there is a "weather window" on Thursday and Friday but the weather was set to change at the weekend.
He said a very detailed search needs to be carried out and it is important that divers are experienced as the terrain is difficult and the search needs to be carried out carefully "so we don't have to repeat and go over the area again".
Mr Kearney said local fishermen were laying a lot of ground lines so divers have a route to follow to make sure the area is "gridded completely".
Holiday home owners and accommodation providers in the Baltimore area are being asked to help with accommodation for up to 40 divers due in the village on Thursday.
Barry Ryan senior, a son of Penneys founder Arthur Ryan, was a senior executive with the retail clothing company.
Ms O'Connor from Glanmire worked at a Penneys store in Cork city.
