Wave Height ("Significant wave height")

Significant wave height is an average measurement of the largest 33% of waves. We measure it because in many applications of wave data, larger waves are more "significant" (important) than smaller waves. For example, the larger waves in a storm cause the most erosion on a beach. 

Significant wave height measured by a wave buoy corresponds well to visual estimates of wave height. This is because most human observers tend to over-estimate the real height of waves. As the significant wave height is an average of the largest waves over a recording period it should be noted that some individual waves might be much larger than this.

The graph below shows the significant wave height recorded by the Canterbury wave buoy over the past week. You can also see the wave height for the past 60 days.