Breaking Waves As waves approach the shoreline, the bottom of the wave comes in contact with the sea floor, and the shape of the wave beings to change. The friction caused by the wave contacting the sea floor causes the circular motion of the wave's base to slow, however, the top of the wave continues to travel at its original speed. The wave begins "leaning forward" and gaining height as it approaches the shoreline. "When the wave's steepness ratio reaches 1:7, the wave's structure collapses on top of itself, forming a breaker," (quote used from http://www.waterencyclopedia.com/Tw-Z/Waves.html). A spilling breaker, is a type of rolling wave that gradually travels up a long sloping beach, the friction encountered by the wave against the sea floor slows the wave over a large distance. A plunging breaker, is a type of rolling wave that travels up a steeper sea floor, and forms a curling top as the base of the wave is slowed due to friction and the top continues to move at its original speed. The photo on the left depicts a plunging breaker. Photo provided by: http://www.waterencyclopedia.com/Tw-Z/Waves.html