Two experienced divers have died in an expedition to a submarine wreck off the Irish coast.
The men, both in their 60s, well qualified and believed to be from England, were in waters about 42m deep off Cork when the tragedy occurred.
One of the men was pulled from the water unconscious and airlifted to Cork University Hospital where he was pronounced dead.
A second man was discovered by a local volunteer crew on a boat after a seven hour search involving the Irish Coast Guard, RNLI and Irish Navy.
The men were understood to be in a party of experienced divers who went to dive on the U-260, an almost intact wreck of a German U-Boat that sank several miles offshore in 1945.
The men got into difficulty 4.5 miles out from Castlehaven and south-west of Glandore bay at about 9.30am.
The group were in an expedition from the Aquaventures Dive Centre, based at Baltimore, west Cork.
It is believed the men may have surfaced after a first early morning dive and went under the water to decompress but did not resurface.
They are the latest diving related deaths in Irish waters in the last month after two men died in separate incidents off Cork and Donegal over one weekend in June.
Relatives of the two divers are understood to be flying in to Cork.
Staff at the dive centre said everyone involved was devastated by the tragedy and that both men were well known to them and had decades of experience.
One of the men completed his first dive in 1967 and both have been known to enthusiasts in the Baltimore area since the late 1970s.
"We have known some of these people for 35 years. It's very, very devastating," a woman at the centre said.
"They were both very experienced divers. They were very, very qualified."
Staff said they were dealing with calls from concerned friends and relatives of the men most of the day.
The search operation was being co-ordinated by the Irish Coast Guard based at Valentia.
The Irish Navy vessel the LE Aisling was tasked to the area to assist in the search operation and the navy dive team was also on scene from early afternoon.
The RNLI crews from Baltimore were alerted at 9.52am.
An inshore and all-weather lifeboats were used in the search and rescue operation.
The Irish Navy said the search area centred around the submarine site just a few miles offshore.
The second diver was recovered on the seabed a few hundred metres from the wreck in water that was around a few metres visibility.
A local dive crew made the discovery.