Duncan Scott, 29, from Newquay, was surfing at Mullagmore Head in Donegal Bay as waves estimated at 55ft (16.7m) high lashed the coast.
Weather forecasters had warned of hazardous conditions for ships, fishing vessels and coastal walkers.
He said that he was safe because friends were on hand with a water bike.
Flood fears
He and Alistair Mennie, Gabe Davies, and Ritchie Fitzgerald, who have surfed some of the biggest breaks in the world, used the water bike to tow them onto the waves.
Mr Scott said: "These were the biggest waves I have ever surfed, but I never felt in danger because we were using experienced riders who were on hand all the time.
"The jet skis have a platform at the rear so you can get back to safety."
It is understood that low pressure near Iceland is causing the high sea levels with waves growing for between 500 and 600 miles by the time they crash against the Irish coastline.
Dr Glenn Nolan, of the Marine Institute, said: "This is allowing waves to travel all the way uninterrupted to the Irish coast.
"It's quite unusual. The last time we would have had waves close to this height would have been in early 2005 and before that in 2000."
Dr Nolan warned that the entire west coast, from Cork up to Donegal, was affected.
Previously the biggest waves recorded by the Marine Institute's data buoys were to the west of Galway Bay in January 2005, when swells of 44ft (13.4m) were recorded.
The high seas come just weeks after the east coast of England braced itself for tidal surges, sparking flood fears and evacuations.
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