"It all happened so fast that all I could do was crouch down as the whale swam under me," Mr Sheridan, 42, said yesterday.
"Next thing I felt was its tail come up and hit me on the back of the head."
"I thought I was gone, but the force eased off and I sailed away with shaking legs."
Mr Sheridan was kiteboarding with two friends off Valla Beach, near Nambucca Heads, when the encounter occurred on October 26. The shots were snapped by a camera mounted on the kite 25m above the water, with frames taken every 10 seconds.
"I just set it up and attach it to my kite and just fire off as soon as I go," he said.
"It was just fortunate the whale came up under me and took a bend. It would have been nice to get it a second later when the tail came up and hit me in the back of the head, but you take what you get."
The whale appeared content to shoo him away, rather than lash out with any aggression.
"It was more of a push than a punch. I expected more," Mr Sheridan said.