Tony McCoy described Campbell Gillies, the jumps jockey who died yesterday, as "easy-going and great company".
Gillies, who would have been 22 today, died after a tragic accident on holiday in Kavos, Greece.
The Scottish-based rider had enjoyed his best season with 38 winners, the highlight being Brindisi Breeze's success in the Albert Bartlett Novices' Hurdle at the Cheltenham Festival.
McCoy said: "He was definitely going places and he was an important part of an increasingly successful team.
"As a person he was easy-going and great company, just the sort of character you need to liven up the Sedgefield weighing room on a wet Tuesday.
"Even if you do not ride you can see the awful irony. You spend all year risking your neck riding horses, you survive relatively unscathed, and then die in a freak accident on holiday.
"It is terribly sad for all his family but it will also be felt very hard in the weighing room, particularly in the north where he spent most of his time.
"When you get news like this it suddenly puts what's important in life into context.
"Ultimately it is a huge waste of talent."
Gillies had gone away with fellow jockeys Nathan Moscrop, Henry Brooke and Harry Haynes, along with Mark Ellwood, head lad at the Kinross stable of Lucinda Russell, to whom he was attached.
Racegoers at Beverley and Brighton completed a minute's silence before racing, with jockeys wearing black armbands.
Paul Bittar, chief executive of the British Horseracing Authority, said: "We are deeply shocked and saddened by the tragic news that Campbell Gillies lost his life in an accident while on holiday in Kavos.
"Campbell was a young, talented and popular rider. At only 21 he had established himself as one of the rising stars in jump racing and enjoyed his first Cheltenham Festival winner this year.
"Sadly this tragic accident means that his outstanding potential will remain unfulfilled.
"At a time like this our thoughts turn first and foremost to Campbell's friends, family and colleagues. On behalf of everyone at the BHA I offer our sincere condolences."
The Professional Jockeys Association released the following statement: "We are shocked by the incredibly sad news of the death of Campbell Gillies and the thoughts of all jockeys and everyone at the PJA are immediately with Campbell's family and friends.
"Campbell was a very popular member of the weighing room and was immensely well liked by his colleagues.
"His riding career was beginning to flourish and he had a great future ahead of him in horse racing.
"In March this year he was able to celebrate a first winner at the Cheltenham Festival on Brindisi Breeze for Scottish trainer Lucinda Russell and there would undoubtedly have been many more days like that for him.
"It is so tragic that he has lost his life at such a young age when Campbell had so much more to look forward to.
"We are liaising closely with the Injured Jockeys Fund who are on standby to provide any support that is required."