An early birthday present has come to the rescue of an Australian snowboarder, whose remarkable ride down a Canadian hillside was eased by his new inflatable avalanche backpack.

Adelaide snowboarder Tom Oye, 29, posted video of the incident on Facebook yesterday, with the footage capturing the moment the snow cracked under foot.

Mr Oye immediately activated his backpack — similar to a car airbag — before a rapid, hair-raising 20-second descent amidst snow and pine trees.

He then ground to a halt as others rushed to offer assistance, but he reassured them: "I'm fine. That was a little scary."

Mr Oye moved to Whistler in Canada three years ago and turns 30 later this month.

His 82-year-old grandmother, Marlene Oye from Flinders Park in Adelaide's west, said his family and friends chipped in to buy him the backpack during a recent visit home.

"It was a lot of money but, my God, it saved his life. It could have been a million dollars but it would have been worth it," she said.

"The gods smiled down upon him.

"I knew when I watched [the footage] that he was all right, so that wasn't quite so bad.

"Having seen him come off motorbikes and that sort of thing, you know, you're a bit prepared I guess. But it was a bit scary."

Ms Oye said her grandson has always been a bit of a daredevil and is also a keen wakeboarder.

"He's got quite a bit of form actually. He's been a very lucky young man because he was an Enduro bike rider here and that gave us enough frights," she said.

Ms Oye said it was not the first time her grandson had run into trouble in the snow, after he suffered a broken leg about 18 months ago.

But she said the latest near miss was unlikely to alter his passion for extreme sports and outdoor adventuring.