You can learn more about waves and the science of surfing at www.exploratorium.edu/theworld/surfing/ (Exploratorium).

Additional information about ocean waves can be found at www.ndbc.noaa.gov/educate/educate.shtml (National Oceanic and Atmospheric Administration).

For surfing news and wave forecasts, go to surfline.com/home/index.cfm (Surfline/Wavetrak). Other surf reports are available at wavewatch.com/ (WaveWatch) and wetsand.com/ (WetSand).

Books recommended by SearchIt!Science:

Powerful Waves — Dorothy M. Souza Published by Carolrhoda Books/Lerner Publishing, 1992. If you've been to the ocean, you know that the water crashes onto the shore in waves, one following the other. Sometimes the waves are gentle, but sometimes they foam and churn. The average wave travels at a speed of about 35 miles per hour. But one kind of wave, a tsunami, can reach speeds of 600 miles per hour. When tsunamis crash onto the shore, they destroy everything in their paths. While waves are caused by the movements of the tides and the winds, tsunamis are caused by earthquakes, volcanoes, landslides, or avalanches at sea. Some of the worst disasters in history have been the result of tsunamis. Color photographs plus drawings and diagrams show how waves form. Some incredible photographs show tsunamis approaching the shoreline and the devastation they leave behind. The book also explains how early-warning systems work and presents safety tips, along with a list of unusual tsunamis.

altimeter An instrument that measures an object's height above sea level. Pilots use altimeters to know how high their airplanes are.

saline Containing dissolved salt. The water in the ocean is saline.

wave A motion back and forth or up and down that passes energy from one point to another. Light, sound, and heat travel as waves of energy. In ocean waves, energy passes through the water even though the water molecules do not have any overall forward movement.