A great white shark has been tracked crossing the Indian ocean from South Africa to Australia and back again within just nine months.
The scientists say the 12,420 mile journey is the longest taken by a fish.
It was one of a group of the beasts tagged in a programme to come up with better ways to save great whites.
They found the sharks, which are under threat of extinction, swam in waters where they're not protected, and were also threatened by fishing boats.
Just getting a tracker onto a great white is a hard task, which involves lots of people holding the shark still while the satellite device is attached.
It was previously thought that sharks stuck to coasts, but this study shows they do swim through big stretches of open ocean.
The scientists think the shark, a female called Nicole after shark-loving actress Nicole Kidman, made its monster trip to find a mate.