Bangor swimmer Jordan Sloan exited from the 200m freestyle heats in disappointing fashion at the World Championships in Budapest.
Sloan's time of 1:49.17 was 1.76 seconds outside the Irish record he set in April as he was 37th overall with only the top 16 making the semi-finals.
His Irish record time would have been 0.01 outside a qualifying spot.
Sloan's team-mate Shane Ryan has progressed to the semi-finals of the 100m backstroke.
Ryan clocked 54.33 which was 0.48 outside his national record set last year.
Sligo swimmer Mona McSharry finished 24th in the women's 100m breaststroke heats with a time of 1:08.52 which was 1.14 seconds outside her national record set in April.