Horrifying video footage captured an Australian surfer desperately trying to get to shore seconds before being mauled by a great white shark that ripped off his leg.

Kai McKenzie, 23, can be seen furiously paddling toward the New South Wales beach, only for a massive gray fin to emerge from the water just behind his board, the video obtained by the Sun showed.

The great white, estimated to be 10 feet long, bit through a chunk of McKenzie’s board — and ripped off his right leg, which later washed up ashore.

McKenzie swatted off the shark and caught a wave back to shore, where an off-duty cop used a dog leash to fashion a makeshift tourniquet around his mangled limb.

The surfer’s severed right leg washed up a short time after the July 23 attack off Port Macquarie. Locals put the leg on ice before it was rushed to the trauma center where McKenzie was being treated so surgeons could assess the possibility of reattachment surgery.

McKenzie later posted a photo on Instagram with his right leg clearly amputated above the knee — suggesting the reattachment had not been possible.

“Spot something missing?” McKenzie captioned the post, adding “so good to have so many amazing people behind me I really appreciate it.”

McKenzie vowed to be “back in the water in no time,” despite the major setback.

The sponsored athlete had only just returned to the waves after taking time off to recover from a neck injury.

A GoFundMe set up to help cover his medical costs has already received more than $114,000 in donations.