In the morning's time trials, Olympic silver medallist Vicky Thornley set the fastest time in the W1x classification, with her Leander teammate Jonny Walton heading up the M1x times to progress to the afternoon's A/B semi finals.
Olympic champion from 2012, Kat Copeland (Leander) stopped the clock fastest in the LW1x, five seconds ahead of her Rio 2016 partner Charlotte Booth (Putney Town). Will Fletcher (Leander) topped the LM1x ahead of Sam Mottram (Leander) and Jamie Copus (Oxford Brookes).
Mat Tarrant (Oxford Brookes) and Stewart Innes (Leander) continued their fine form, having taken the M2- honours at the third winter assessment, by setting the fastest time at Caversham, while Fiona Gammond and Katherine Douglas (both Leander) were quickest in the W2-.
Edinburgh University youngster Josh Armstrong secured his place in the M1x final with a strong semi-final performance in his first trials appearance. He joins Leander quintet Walton, John Collins, Jack Beaumont, Pete Lambert and Tom Barras in Sunday's final.
Jessica Leyden (Leander) goes into the W1x A final with the fastest time, winning her semi ahead of Matilda Hodgkins-Byrne (Reading/Reading Univ) and Emily Carmichael (Leander). Thornley took the second semi, with Bethany Bryan (Leander) and Georgia Francis (Imperial College) joining her in the final.
Mottram and Fletcher built on their strong time trials by taking first in both the LM1x semi finals, as did Copeland and Booth in the LW1x. The Leander boys are joined in the final by Copus, Peter Chambers (Oxford Brookes), Edward Fisher (Leander), Zak Lee-Green (Agecroft).
Cambridge University duo Melissa Wilson and Holly Hill beat time trial winners Gammond and Douglas to the line in the second semi-final of the W2-, with Bennett and Norton taking the first race ahead of Sara Parfett (Univ. of London) and Annie Withers (Oxford Brookes). Rebecca Girling (Molesey) and Caragh McMurty (Southampton Coalporters), and Rebecca Shorten (Imperial College) and Josephine Wratten (Leander) also go through to the final.
The men's pair looks to be a hotly contested battle on Sunday, with Satch and Sbihi taking the fastest time into the final, just over a tenth of a second quicker than Tarrant and Innes in the second semi. Matt Rossiter and Jacob Dawson (both Leander), Oliver Cook (Oxford Univ) and Lance Tredell (Cambridge Univ.), Sam Arnott and Thomas Jeffery (both Leander), and James Rudkin and Callum McBrierty (both Leander) make up the rest of the final lineup.