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.
Weekend Cold Snap To Provide Brisk Shake Up To Interminable Rainy Monotony
Greystones Fishermen Still Struggling Despite Harbour Settlement Warns Senator
Kilkenny Hurling Legend Helps Wicklow GAA Expand Profile With Fans App
New Plan Approved For Greystones Delgany Kilcoole.
Rás Tailteann Returns to Wicklow with Baltinglass Stage Finish