The incident happened off Wexford's Hook Head this evening.
The father of four in his forties was taking part in an underwater search for a fisherman who went missing from a trawler off the Saltee Islands yesterday morning.
The alert was raised shortly after noon today as he returned to the surface after a dive.
He was treated by colleagues at the scene and airlifted to University Hospital Waterford where he has since been pronounced dead.
Caution Urged On The Coast As Storm Austen Approaches
Swimmers are advised to avoid entering the water in stormy weather, or when strong winds, waves or currents make conditions unsafe.
Local Shock As Couple Found Dead At Their Bray Home
Gardaí are treating the case as a tragedy, and await post mortem results.
EirGrid Seeks Views On New Substations For North Wicklow
The North Wicklow Reinforcement Project will reinforce the electricity grid in North Wicklow, ensuring sufficient capacity is available for future increased demand.
Wicklow Receives 363 Applications For Vacant Property Refurbishment Grant
Over 120 previously vacant and derelict properties have been restored to residential use across Wicklow through the Vacant Property Refurbishment Grant
Storm Austen Warning for Wicklow With Heavy Rain Bringing Flood Risk
Difficult driving and localised flooding are possible from 7pm Thursday, with more wet and windy weather lined up for the bank holiday weekend.
Sunny intervals
High: 12°C | Low: 6°C
Sunny intervals
High: 12°C | Low: 7°C
Heavy rain shower
High: 12°C | Low: 6°C
Sunny intervals
High: 12°C | Low: 5°C
Heavy rain shower
High: 12°C | Low: 6°C
