created the original "Long board", which made him the talk of the islands. To the delight of visitors, Freeth exhibited his surfing skills twice a day in front of the Hotel Redondo. Another native Hawaiian, Duke Kahanamoku, spread surfing to both the U.S. and Australia, riding the waves after displaying the swimming prowess that won him Olympic gold medals in 1912 and 1920. In 1975, a professional tour started. That year Margo Oberg became the first female professional surfer. Surf waves Swell is generated when the wind blows consistently over a large space of open water, called the wind's fetch. The size of a swell is determined by the strength of the wind, and the length of its fetch and duration. Because of these factors, the surf tends to be larger and more prevalent on coastlines exposed to large expanses of ocean traversed by intense low pressure systems. Local wind conditions affect wave quality since the surface of a wave can become choppy in blustery conditions. Ideal conditions include a light to moderate "offshore" wind, because it blows into the front of the wave, making it a "barrel" or "tube" wave. Waves are left-handed and right-handed depending upon the breaking formation of the wave. Waves are generally recognized by the surfaces over which they break. For example, there are beach breaks, reef breaks and point breaks. The most important influence on wave shape is the topography of the seabed directly behind and immediately beneath the breaking wave. Each break is different since each location's underwater topography is unique. At beach breaks, sandbanks change shape from week to week. Surf forecasting is aided by advances in information technology. Mathematical modeling graphically depicts the size and direction of swells around the globe. Swell regularity varies across the globe and throughout the year. During winter, heavy swells are generated in the mid-latitudes, when the North and South polar fronts shift toward the Equator. The predominantly Westerly winds generate swells that advance Eastward, so waves tend to be largest on West coasts during winter months. However, an endless train of mid-latitude cyclones cause the isobars to become undulated, redirecting swells at regular intervals toward the tropics. East coasts also receive heavy winter swells when low-pressure cells form in the sub-tropics, where slow moving highs inhibit their movement. These lows produce a shorter fetch than polar fronts, however, they can still generate heavy swells since