Marshall's winning time was not fast enough to qualify

Marshall clocked one minute 58.50 seconds, just 0.14 outside the standard of 1min 58.36secs.

Todd Cooper also missed a qualification time in the 100m butterfly, although his 53.53secs was enough to win.

Kristopher Gilchrist won the 200m breaststroke while Robin Francis edged a close men's individual medley.

Elsewhere, 14-year-old Elizabeth Simmonds narrowly failed to secure her first national title when she missed out in the 50m backstroke to Gemma Spofforth.

The produced two impressive performances which bode well for tomorrow's final.

In the first of the men's 200m freestyle semi-finals, Ross Davenport set a personal best of 1:48.68 before David Carry responded in the next race by setting a new Scottish record of 1:48.37.

Liam Tancock and Matthew Clay followed the freestylers' example in the 50m backstroke.

Tancock won his semi in 25.75secs before Clay set a new Welsh record of 25.94secs.

Jessica Dickons was the fastest through in the semis of the 200m butterfly, Kirsty Balfour occupies pole position as she goes for the 200m breaststroke crown and Stacey Tadd was fastest in the 200m individual medley.