With a powerful dive a polar bear launches herself with startling speed into the frigid arctic waters. Polar bears (ursus maritimus), not having to fear any natural enemies in their natural environment, are the grand lords of the Arctic. They are very good swimmers, which in combination with the rather big body and strength makes this predator a threat for many that might end up as part of the menu both above and underwater. Here we get a less common glimpse of the underwater world. With beams of mottled sunlight penetrating from a calm surface, there is an indication that above the water, the day is sunny and perhaps not as cold as it could be. Underwater, however, business is serious; a very fast chase after a so far elusive target, but for how long that lasts we do not really know...