Who is watching Dublin's skies and seas during the EPC summit?

Aircraft could be heard circling over Dublin throughout the morning and afternoon as European leaders gathered for the EPC summit.

Their movements offer a glimpse of the security operation extending beyond the barriers and road closures on the ground.

Public flight-tracking data from flight-radar website ADS-B Exchange reviewed by RTÉ showed at least six Air Corps and Garda aircraft have been airborne around Dublin today.

These included a Garda Air Support Unit helicopter and a small surveillance plane, a Twin Otter, flying repeated circuits over the city.

Two Irish Air Corps AW139 helicopters were seen on the radar circling over Dublin city and Dublin Bay with the call signs WOLF1 and WOLF2.

These are general utility aircraft which provide army support, air ambulance and military transport.

Further offshore, an Air Corps Airbus C295 maritime patrol aircraft, using the callsign KRAKEN, flew over the Irish Sea along the coast between Dublin and Wexford.

An Air Corps Pilatus PC-12 aircraft, whose roles include intelligence, surveillance and reconnaissance, was also tracked over Co Kildare, having departed from Casement Aerodrome at Baldonnel.

Those tracks establish where the aircraft were flying. They do not, on their own, establish each crew's assignment or provide a complete picture of the security operation.

Not every military aircraft appearing on flight trackers is involved in protecting the summit, and not every military aircraft or vessel will operate with its transponder turned on. Military aircraft and vessels can and do operate with their location visibility off during certain operations for security reasons.

Several foreign air force aircraft also arrived in Dublin this morning, including two from the French Air Force and one from the Portuguese Air Force which landed at Casement Aerodrome, apparently transporting delegations to the summit.

Closer to the venue of the summit, gardaí have deployed drones near the Convention Centre to support its policing operation.

Gardaí said the drones will be active until after the policing operation has ended. They also confirmed that a temporary restricted airspace is in place across Dublin until Saturday, including restrictions on drone flights.

Counter-drone systems are also in place to detect unauthorised drones and locate their operators, according to gardaí.

At sea, vessel tracking website MarineTraffic showed the Irish Navy's LÉ James Joyce patrol vessel positioned off the Dublin coast.

Access to the waters closer to the summit venue is also being controlled. A maritime exclusion zone covers the River Liffey between Seán Heuston Bridge and the Tom Clarke Bridge, also known as the East Link, with entry requiring garda authorisation.

A wider control area extends into Dublin Bay, where commercial shipping can continue subject to additional security controls. Both measures remain in place until midnight tomorrow.

The Department of Transport has said that all vessels deemed a risk to the security situation will be controlled in this area and that entry to this zone will be permitted for vessels that are not deemed a risk.

The extent of foreign naval involvement is less clear.

Former justice minister Senator Michael McDowell said last week that Ireland was relying on a French naval vessel to help secure Dublin’s airspace during the summit. He said the Air Corps lacked aircraft capable of defending Irish airspace.

The French Navy frigate FS Aconit was seen leaving Glasgow on Tuesday and is listed by Dublin Port as due to arrive here on Saturday.

It has not been established whether Aconit is the vessel Senator McDowell was referring to or whether it is supporting the summit’s security operation.

The Defence Forces said that Operation Fianna, which supports security during the Irish EU Presidency, involves more than 700 soldiers, sailors and aircrew delivering "specialist capabilities in support of national security".

In a statement, it said the Air Corps continues to conduct operations in Irish airspace while the naval service conducts maritime defence and security operations in the Irish Sea.

The Defence Forces said that for operational security reasons, it does not comment on specific tasking, deployment or operational deployment of individual assets.