There are no plans to scale down searches for two people feared dead after the microlight they were travelling in crashed around Glenarm.
Sean McCarry from the Community Rescue Service (CRS) said they look set to continue despite meeting with no success throughout the weekend.
The flight carrying two people - who are not believed to be from Northern Ireland - had originally taken off from City of Derry Airport on Thursday and had been tracking towards Stranraer in Scotland.
After wreckage from the missing microlight was found in the sea north of Glenarm on Friday, a major land, sea and air search was launched.
The PSNI and CRS last night remained tight-lipped on the identities of the missing pair.
Sonar teams combed the area in seven-mile sections on Sunday.
Mr McCarry said: “We will be searching right through the night, if necessary – and we will keep searching until we are told to stop. We will do as much as we can. We cannot search the whole of the Irish sea but we will do as much as we can.”
Geordie Canavan, who is also from the Community rescue Service, said: “Sonar teams have been deployed offshore where they are viewing images below the water.
“At the minute they are using it at 150ft. It floats above the bottom and it gets the image on either side.”
He added: “It is meticulous. We have used it in the Lagan and all over the country. They are doing it in around 7-8 mile runs each time, going back and forward around what they call the hot zone.
“We are trying to get an indication if there is anything below the surface.”
Mr McCarry said “around 40 people from CRS were involved in the search” on Sunday.
He said teams had been also combing the coastline.
The microlights had been heading towards Castle Kennedy airfield, a disused airfield outside Stranraer.
Earlier Inspector Michael McDonnell of Ballycastle Neighbourhood Policing Team said: “Our thoughts are with the families of those involved. Specialist officers are providing support to the families at this very difficult time.
“The PSNI will continue to assist in this search operation and we will investigate this incident in partnership with other agencies.
“I would appeal to anyone who may have any information which could help in any way to contact police on the non-emergency number 101.”
Wreckage from the missing micro light began to be brought ashore on Saturday evening.