Sydney: A terrified Australian clung to the remains of his kayak for 40 minutes but survived in one piece after a shark took a huge bite out of the boat.

Gavin Kleidon’s ordeal began late Sunday as he was paddling in a leisurely fashion to Mud Island in Moreton Bay off Brisbane. Then the shark attacked from behind.

Kleidon told the Australian Broadcasting Corporation he never saw the predator but knew immediately what had happened.

“I saw the back of my boat floating away and I knew pretty quickly what it was,” he said.

“I tried to climb on my boat as quick as I could. It was sinking pretty quick, which was stressing me out a bit. I looked for my paddle but unfortunately it had drifted away.”

As he lay on top of what remained of his kayak, waves crashed overhead.

But he managed to keep his nerve and pull his phone from its waterproof casing and call emergency services.

Kleidon said he had a “fair idea” of his location because of landmarks on the shoreline but endured a nervous 40-minute wait as marine police scrambled to find him, with passing planes heading into Brisbane airport helping track him.

“I was very nervous at that stage to know that it [the shark] could’ve moved on pretty quick, or it could’ve still been around. I just wasn’t sure at that stage,” he said.

Experts say shark attacks are increasing as water sports become more popular and bait fish move closer to shore, but fatalities remain rare.