Close call: Watch the moment a huge hippo CHASES a speedboat full of sightseers!

This terrifying footage shows the moment a group of sightseers took a boat out to look for hippos - only to end up being CHASED by one of the huge animals.

Hair-raising footage shows the massive animal gliding through the water in the wake of the speedboat - mostly underwater, but occasionally rearing its head to breathe as it continues to follow the boat.

The shocking incident took place on May 23 on the Zambezi River in Livingstone, Zambia.

Hippos can measure up to five metres in length and can weigh a whopping 1,500kg (235 stone).

They are considered to be the world's deadliest land mammal, killing up to 500 people a year in Africa.