The northern coasts of the Hawaiian Islands are world-renowned for their remarkable winter waves. From October through April, huge storms in the Gulf of Alaska and Bering Sea frequently develop hurricane-force winds that follow the storms, but the waves spread out in all directions and, when conditions are right, travel 2,000 miles south to Hawaii. As the ocean becomes shallow near the northern shore of Oahu, the waves are forced upward, reaching heights of 50-70 feet or more when the direction of movement combines with just the right shape of ocean bottom.
As the waves become extremely tall, their dynamics become chaotic, and they break, curl and collapse. These waves are sought out by daredevil surfers from around the world. On the southern side of the islands, locations such as Honolulu do not get these big waves because the tropical weather south of Hawaii is not prone to be stormy during winter.