A bore tide is a phenomenon in which a tide that creates a wave goes against the current of a narrow body of water. Bore tides typically occur after extreme minus low tides created by the full or new moon. There are just a few places in the world where this occurs -- extremely few in North America. One such place is Turnagain Arm in Cook Inlet. Each season, the bore tide brings kayakers, surfers, and paddle boarders to Southcentral Alaska, to ride the waves. In some parts of Asia, bore tides can reach up to 30 feet high. The ones in Alaska are closer to 6 feet, but they are considered some of the largest because of the length of the waves, at times more than 40 miles. The word bore derives through Old English from the Old Norse word bára, meaning "wave" or "swell".Whitewater kayakers Chad Hults and James Russell set out April 4, 2014 take on the bore tide. The result is a wonderful ride using a natural phenomenon in Anchorage’s backyard. Be sure to watch them ripping the second wave farther down Turnagain Arm past Girdwood, action set to the tune of "Riders on the Storm." The official 2014 tide schedule is distributed by Chugach State Park.