A Canadian daredevil appears to have broken the world record for free soloing a slackline earlier this month in Squamish, B.C., according to a new video of the event posted on YouTube.

In the video, Spencer Seabrooke can be seen coming close to falling several times, as he crosses the 64-metre gap at the North Gully of the Chief mountain, 290 metres off the ground without a safety harness, breaking the prior record by seven metres, according to the post.

The crossing was made on Aug. 2, but the video was only posted on Tuesday. Prior to the record attempt Seabrooke, who is originally from Ontario, warmed up by crossing the line once with a harness.

Spencer Seabrooke made 64-metre crossing almost 300 metres in air without harness 1:32

Slacklining is similar to traditional tightrope walking, but the inch-wide nylon webbing is rigged with enough slack to allow it to sag and sway beneath the walker.

While many slackliners practise the sport around a metre off the ground, using a line strung between two trees in a park for instance, daredevils like Seabrooke pursue a branch of the sport called highlining, crossing gaps hundreds of metres in the air.

Record attempt 'gut wrenching'

"This had to have been one of the most gut wrenching things I've experienced in my whole life, between operating the drone and watching him walk 290 metres above the Earth's floor. It was definitely something I have never experienced," said videographer Zackary Moxley in the YouTube post.

Seabrooke took up the sport only three years ago, but this is not the first time the extreme athlete has made his mark at the Chief, a granite monolith north of Vancouver, which has been a popular destination for hikers and rockclimbers for decades.

In 2014, Seabrooke was featured in a video from the second annual gathering of world class slackliners at the site.

The gully, also known as the Itus, has also been the focus of other slacklining videos in recent years.