Some of Hawaii's beaches have been shut down as officials fear 50-foot waves could pummel the coast today. However, even as residents are being advised to avoid the shore, some surfers are expected to take advantage of the situation. Strong winds in the northwest Pacific Ocean and "unusual high tide levels" are fueling the towering waves. Officials are urging people to avoid the northern shores of most of the islands, but lifeguards say those warnings probably won't be heeded by some surfing enthusiasts. One group is expected to take part in a seldom-held tournament today. The invitational is held only when the waves reach at least 20 feet. It has been held only six times in 19 years.