The world of Formula One has paid tribute to former medical delegate Sid Watkins who died on Wednesday night at the age of 84.
Watkins, an on-track surgeon for 26 years from 1978 through to 2004, led a crusade to improve medical facilities in Formula One, helping to dramatically cut the number of deaths and serious injuries in the sport.
Throughout his career in F1, Watkins' actions helped save the lives of Northern Ireland's Martin Donnelly, Finland's double world champion Mika Hakkinen and Austrian Gerhard Berger, among others.
Watkins worked tirelessly to improve safety in the cockpit, on the track, and the medical support at circuits alongside the likes of Britain's triple world champion Sir Jackie Stewart and FIA president Max Mosley.
Confirming Watkins' passing, McLaren Group chairman and close friend Ron Dennis said: "Today the world of motor racing lost one of its true greats.
"No, he wasn't a driver. No, he wasn't an engineer. No, he wasn't a designer. He was a doctor and it's probably fair to say he did more than anyone, over many years, to make Formula One as safe as it is today.
"Many drivers and ex-drivers owe their lives to his careful and expert work, which resulted in the massive advances in safety levels that today's drivers possibly take for granted."
One driver who credited Watkins for saving his is Rubens Barrichello, who suffered a huge crash during qualifying for the San Marino Grand Prix at Imola in 1994, the same race that claimed the lives of Roland Ratzenberger and Ayrton Senna.
Barrichello, now racing in Indycars in the United States, tweeted:
Other F1 drivers tweeted their appreciation of Watkins, including Lewis Hamilton and Jenson Button while former driver and BBC commentator, David Coulthard, said that "Sid Watkins was one of the best men I have met in my life, totally selfless".
Watkins was a close friend of Ayrton Senna and was deeply upset when the triple world champion was killed at Imola. He returned to the public eye last year in the film, Senna, when he recalled trying to persuade the Brazilian to give up racing at Imola after Ratzenberger's death.
He told Senna: "What else do you need to do? You have been world champion three times, you are obviously the quickest driver. Give it up and let's go fishing."
F1's current medical delegate Gary Hartstein, who learned his trade for seven years under Watkins' wing, said: "For a long time I wanted to call him every time I had to make a decision. Then I just started thinking 'what would he do in this situation?'
"And finally, for better or for worse, I realised I was doing just what he'd do (but probably not as well).
"He kinda had a big place in my life for a long time. Just about the most extraordinary person I've known."
Watkins became the first Professor of Neurosurgery at the London Hospital in 1970 when he was also appointed to the RAC medical panel.
He was approached by Formula One ringmaster Bernie Ecclestone in 1978 to become an on-track surgeon at grands prix and he was also the chief medical officer for FIA, the sport's world governing body.
Upon stepping down, Watkins focused on his role as president of the FIA Institute for Motor Sport Safety through to December last year, continuing only in an honorary position.