Here's why:
* They're incredibly well-insulated: Their thick layer of blubber and dense fur makes them resistant to freezing temperatures and keeps them warm in the icy waters.
* They're incredible swimmers: Polar bears can hold their breath for an astonishingly long time and swim long distances. Their large paws with non-retractable claws help them propel themselves through the water.
* They're expert hunters: They have a keen sense of smell, allowing them to detect seals from miles away. They are incredibly patient and can wait for hours by breathing holes in the ice or at seal haul-outs.
* They're powerful: Polar bears are the largest land predator in the world and are incredibly strong, allowing them to take down large prey like seals.
All of these adaptations combined make them incredibly efficient and successful hunters in the harsh Arctic environment. It's a truly amazing testament to the power of evolution!