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Convention for describing wave direction

Users should note that by convention the direction of waves (and hence also wave energy flux) is described as the direction the waves are moving towards.  This is opposite from the convention for wind direction which is defined as where the winds are coming from.  Thus a southwesterly wind blows from the southwest; the corresponding wind-sea moves towards the northeast and is a thus described as a northeasterly wind-sea.

Wave Height definitions

The wave height is the distance between trough and crest.  However, many waves co-exist at the surface of the ocean and their distribution is given by the 2D wave spectrum.  From this distribution, the significant wave height is defined as 4 times the square root of the integral over frequency and direction of the wave spectrum.  It can be shown to correspond to the average wave height of the one-third highest waves, commonly known as H_1/3.  The mean wave direction is the spectrally averaged propagation direction of the waves (weighted by amplitude).

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