GoPro Shark Attack: Man Jumps Into Sydney Harbour, Immediately Confronted By Great White

If you absolutely have to live in a country so full of deadly bugs, sea creatures and snakes that it might as well be owned and operated by that tribe from Indiana Jones, don't jump into the harbour without checking for sharks.

Unfortunately that's not advice one Australian equipped with a GoPro camera felt it necessary to take, according to this video.

If you take the clip as it appears (it's possible it's fake) this man leaped into Sydney Harbour and only realised something was wrong when his friend still on the cliff shouted, succinctly, "shark".

What happened next is mind-bogglingly terrifying.