And then there are moments like these in the Speedo LZR Racer: In the 200m medley. Hannah Miley, an 18-year-old from Aberdeenshire, had held the British record at 2:14.10. She now holds it at 2:11.46, a time that catapulted her from 60th on the all-time list to 9th. The time would have won silver at the European Championships two weeks ago in Eindhoven but Miley was absent.

And in her wake came Kerri-Anne Payne, of Stockport Metro, on a 2:12.42, an improvement from a previous best of 2:17.28, or in other words from outside the top 300 fastest swimmers all-time to 21st.

Such improvements are breathtaking, even beyond the natural breathlessness of swimmers emerging from races. Payne, who missed qualification to the 2004 Olympic Games in Athens four years ago by a fingernail, said: 'I can't believe that time. I have to say the suit has made a difference. There is no other explanation. I felt terrific.'

Payne, like Miley, must finish top two in the finals tomorrow morning. She will then be facing an interesting Olympic journey: 200m medley, possibly followed by a 10km open water swim: a distance specialist Payne, coached by Sean Kelly, will attempt to qualify for the inaugural Olympic marathon open-water race at trials in Seville in May.

Miley, coached by father Patrick in Garioch, said: 'That felt strong. It was about getting the time. Tomorrow will be all about getting in there and making it. I just want to make the team.'

In the 100m breaststroke heats, Kate Haywood, coached by Ben Titley at Loughborough, set a national mark of 1:07.56, up from 32nd to 18th all-time. The 50m freestyle saw Francesca Halsall, 17 and coached by Colin Stripe in Liverpool, dip below 25sec for the first time, her 24.72 just 0.04sec shy of the British record held by Alsion Sheppard since 2002 and an effort that lifts her from 52nd on the all-time list to 17th equal alongside Olympic 100m champion Jodie Henry (AUS).