In water, the shark dominates. On ice, the bear wins. Most realistic encounters favor the shark.
Polar bears swim in Arctic waters where great whites occasionally patrol, but these encounters are extremely rare. In the water, the shark's speed and ambush-from-below attack are devastatingly effective. On ice, the polar bear is safe.
The great white's estimated 4,000 PSI bite could severely wound a polar bear in a single strike. From below โ the shark's preferred angle โ the bear would have no warning and no defense.
On an ice shelf, the polar bear is completely safe. But if it enters the water โ as polar bears regularly do to hunt seals โ it becomes vulnerable to the shark's aquatic superiority.
The polar bear is a powerful swimmer and fighter. On ice, it's completely dominant. Its paw swipes could injure the shark if it surfaces.
The shark is faster, more maneuverable in water, and has a devastating ambush attack from below. Its bite force exceeds the polar bear's. In the water, the bear loses all its land advantages.
The shark wins in aquatic encounters. The polar bear wins on ice. Since realistic encounters happen at the ice-water interface, the shark's ambush ability gives it the edge.
Polar Bear also fights
Great White Shark also fights