In 1965, Symons was drafted by the NFL's Green Bay Packers, but an injury led Vince Lombardi to cut him.
The next year he started his CFL career with the BC Lions playing 10 games, most at the defensive safety position. At the end of the 1966 season Symons was dealt to Toronto. In the 1967 season Symons picked up 349 yards rushing positioning himself as a starter.
Everything came together in 1968, when Symons rushed for 1,107 yards. He was the first Boatman, ever, to top the 1,000 yard plateau. Added to this record was his CFL's Most Outstanding Player Award, again a first for any Double Blue player, and a CFL All-Star at running back. The only thing missing was a trip to the Grey Cup, Unfortunately, their trip to the 59th Grey Cup ended in classic heartbreak.
In his final two seasons with the boatmen Symons' role was a blocking back rushing for 235 yards in 1972 and 358 in 1973. Symons called it quits after 1973. For his great performances as a running back, Symons was inducted into the Canadian Football Hall of Fame in 1997.