Paul O'Higgins's JPK 10.80 Rockabill VI took line honours, first in IRC overall and first in Class Zero in Saturday's 23-mile race ten of the ISORA Series.
In a southerly 15-18 knot breeze, the six-boat fleet started off Dun Laoghaire Harbour under Race Officer Michael Horgan at 10 am.
The fleet left Muglins Rock at the southern tip of Dublin Bay to starboard, sailing down the coast to round Moulditch buoy off Greystones Harbour in County Wicklow before returning to the Bay, leaving the Muglins to Port and a finish off Dun Laoghaire Harbour.
The Royal Irish line honours winner completed the course in four hours, 24 minutes and 31 seconds.
Second in IRC overall was Leslie Parnell's First 34.7, which was sailed double-handed. Third place in IRC overall, and the IRC Class One winner was the Shanahan family's J109, Ruth from the National Yacht Club.