The nation's top rowers will face one of their sternest tests yet this weekend as the GB Rowing Team whittles down its potential Rio 2016 squad.
Olympic Champions Alex Gregory, Pete Reed, from Gloucestershire, and Yorkshire's Andy T Hodge, coming back after a long lay-off, will be amongst those racing two consecutive time trials followed by side-by-side finals.
This trio of London gold medallists will race in a strong men's pair field from which Gregory and Surbition's Mohamed Sbihi are favourites to win.
Sbihi races at the weekend after a triumphant British Rowing Indoor Championships in which he smashed Sir Matt Pinsent's 11 year old 2k indoor rowing record.
He talked of the emotion involved this weekend when he said: "It is another important step towards Rio. The trials process is never fun - you are racing your teammates and friends - but it is important in making our team as strong as we can be for the summer. Of course there is tension, every day that passes is moving closer and closer to Rio and everyone wants to get the best result possible to strengthen their chance of going to Rio."
The scene is also set for a top-line tussle in the open women's single scull between Wrexham's Vicky Thornley, winner of the last two GB trials, returning Olympic gold medallist Anna Watkins, from Leek, and her 2012 title-winning partner Katherine Grainger, from Glasgow, as well as challengers like London's Melanie Wilson.
Penzance's Helen Glover won the equivalent trial a year ago and will also be in the mix for top spot even though she and her Olympic Champion partner Lossiemouth's Heather Stanning will be seeking selection into the sweep oar rather than sculling events in Rio.
Thornley summed up the tension when she said: This is a really important trial being the last one before we enter 2016 and the last one before final Olympic trials in March. I am looking to finish this year with a really solid performance and show how I have improved.
There is so much more at stake this season, the Olympics is what we do this all for. It's very important that I bring my best at every trial to put myself in the best position to be in a boat with the best chance of a medal.
On Saturday the open women's title will be decided by accumulation of the two time-trial results with a 2km row back to the start in between the two tests.
In the open men's single scull event, Sam Townsend, Jonny Walton and John Collins who took the top three spots in the autumn over a 5km distance. Charles Cousins, from Cambridgeshire, winner of last season's final set of trials, is training fully but is not quite ready to race yet according to the coaching team.
Coleraine's Alan Campbell is returning to the kind of form that saw him win a 2012 bronze and will be amongst the contenders to win on Saturday. Graeme Thomas, 2013 and 2014 World quad medallist will be in action after missing the autumn trials.
Brothers Richard and Peter Chambers, also from Coleraine and both 2012 lightweight men's four silver medallists, were the fastest two finishers in October in the lightweight men's single scull with Chester-le-Street's Will Fletcher not far behind.
Imogen Walsh, from Inverness, got the better of Olympic Champion Kat Copeland, from Teesside, over the longer distance and, on Saturday, Putney's Charlotte Taylor is also fit to race. These three women are among the top contenders for a seat in the only Olympic boat for lightweight women - the double scull.
Walsh said: Trials are obviously quite nerve-wracking, but it's also exciting, in that it's an opportunity to prove to yourself and to others what you are capable of. Obviously, everybody's minds are on selection and performance in the summer, but the only way to get to the position you want in the summer is to prove your worth in the trials in the winter.
None of us in the team would be here if we didn't enjoy racing, so while there is obviously a lot riding on our results across the season's trials, for me anyway, trials are something to try and enjoy as well… Although I might not say quite that on Saturday morning.
Alongside trials for the Rio squad, a number of rowers will be seeking to impress the selectors and coaches in time for next year's World U23 Championships in Rotterdam.
The nation's top para-rowers will be put through their paces on Saturday in a closed test on indoor rowing machines (ergos).