Breaking waves- waves break when the depth of the wave reaches 1/2 of its wavelength. The wave starts to "feel bottom" and slows down due to friction. The top part of the wave continues at speed and outruns the bottom of the wave. Gravity will then pull the top part of the wave down causing it to break.
Wave size depends on three factors: fetch-distance wind can travel uninterupted, wind speed and how long the wind blows.
Upwelling- cold water from depth replacing warmer water from the surface.