F1's medical delegate between 1978 and 2004, the British neurosurgeon not only helped to revolutionize safety standards in the sport and save countless drivers' lives, his was an infectiously lovable personality.
A wise-cracking lover of cigars and whiskey, he saved drivers including Rubens Barrichello and Mika Hakkinen, was there when Roland Ratzenberger and his great friend Ayrton Senna died, and he nursed Sir Frank Williams back to health after his car crash.
"I remain forever grateful to him," Williams said on Thursday.
David Coulthard added: "Sid Watkins was one of the best men I have met in my life."
Watkins died on Wednesday evening after a battle with cancer.