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.
Extra Lifeguards Deployed With Extended Hours On Wicklow Beaches This Week
The Irish Coast Guard is urging anyone planning an activity on or near the water to keep safety in mind, and be aware of the serious risk of cold-water shock.
Bus Service Boost For Wicklow with Connections to Carlow & Kilkenny
A revised local link route will provide direct access to Arklow Train Station from Monday.
Greystones Man Given Suspended Sentence Following Sustained Campaign Of Abuse
A 'sustained, persistent and vile' campaign against an unsuspecting former golf manager in Co. Wicklow after one man was left aggrieved by decisions made at Druid's Glen
Appeal for Information As Rathdrum Man Reported Missing
Wicklow House Prices Stabilise As Increased Supply Takes Heat Out Of Market
After several years of growth, the county's property market is beginning to cool
Sunny intervals
High: 24°C | Low: 17°C
Sunny intervals
High: 22°C | Low: 16°C
Sunny intervals
High: 24°C | Low: 17°C
Thundery shower
High: 26°C | Low: 17°C
Sunny intervals
High: 25°C | Low: 17°C
