A self‐similar spectral shape (the TMA spectrum) to describe wind waves in water of finite depth is presented. The parametric spectral form is depth dependent and an extension of the deep water JONSWAP spectrum. The behavior of the spectrum in frequency and wave number space is discussed. About 2800 spectra selected from three data sets (TEXEL storm, MARSEN, ARSLOE) are investigated to show the general validity of the proposal self‐similar spectral shape.

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There are indications that the mean significant wave height at Seven Stones Light Vessel has increased in the period 1960-85. This is of considerable interest for the design of offshore structures and for coastal defense. In this note, the authors present new results based on the analysis of a collection of more than 20 000 hand-drawn wave charts. These charts were produced routinely between 1960 and 1988 in a manner that remained essentially unchanged throughout this period. The results are in remarkable agreement with the trend observed at Seven Stones Light Vessel.

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The equations describing refraction of water waves are based on the geometrical optics approximation, in which wave rays are calculated independently of each other. For this reason the model reacts sensitively to small variations in depth as well as in incident wave frequency and direction. This leads to an uncertainty in the interpretation of the location of individual rays, particularly in cases of large travel distances through regions with weakly irregular bottom topography, as in shelf seas. In this paper, this uncertainty is taken into account from the outset by treating the results of the ray calculations as a case of statistical sampling, in which a tradeoff is made between resolution and confidence. To this end, the area being studied is divided into a number of subregions (bins), in each of which the total wave energy is estimated from the rays passing through it, each ray being considered as a carrier of a certain amount of wave power. The size of the bins determines the spatial resolution. It must be chosen in conjunction with the discretization intervals for ray separation, frequency, and direction, considering also the propagation distance, the length scale of the target area, and the bottom topography. This is illustrated with an example from JONSWAP.