Malahide sailor David Burrows slipped from a starting 14th to 22nd in the 11th and final race of the Finn class in Athens this afternoon, finishing 12th overall, 78 points behind British gold medalist Ben Ainslie.
The 27-year-old needed a good run of final races in the single-handed Dinghy class, having been 10th at halfway, to beat his Sydney finish of ninth - Ireland's best sailing result since 1980 - but two top-five places were not enough.
Dun Laoghaire's Ger Owens and Ross Killian finished off their week's work in the 470s with tenth place, nearly two minutes behind Russian race winners Dmitry Berezkin and Mikhail Krutikov.
The Irish duo ranked 16th overall, with Americans Paul Foerster and Kevin Burnham claiming gold.
Ireland's last hope of a sailing medal at the Agios Kosmas centre, Mark Mansfield and Killian Collins finished a disappointing 11th and 15th results in their first races in the Star class.
World-ranked fifth, the Cork pairing are 15th overall of a fleet of 17.