Here's why:
* Built for swimming: Polar bears have evolved to be powerful swimmers. They have large, paddle-like paws and a streamlined body that helps them move through the water with ease.
* Powerful stroke: Their powerful legs and strong back muscles propel them through the water with incredible speed.
* Endurance: They can hold their breath for a long time and swim for extended periods, allowing them to chase prey underwater.
While exact speed comparisons are hard to find, it's safe to say a polar bear can easily outswim a human.