WIND-and-WAVES - V.44

Author: Heiner Müller-Krumbhaar

knots hours
Wind   Time
km ±knots
Fetch   Current

WAVES for Windspeed = Beaufort
m m secs
Height Length Period


WAVES - depending on Wind, Time and Fetch,
and Current and Depth near the Coast

This program calculates the height of ocean-waves H depending upon the strength of the wind and the time of its duration, and also depending upon the fetch (range of open water). Furthermore wavelength L and period T are calculated [1]. For waves approaching the coast, currents may become important. Negative values for ebb-currents against the waves, positive for flood towards the coast. The model for waves in shallow water (depth D small against wavelength L: Hmax= 0.14*L*tanh(2πD/L) assumes [2] here that the waves have been generated by wind in deep water, approaching shallow water near the coast. This may cause dangerous breakers. In a completely flat large shallow area, wave-heights will not exceed Hmax= 0.88*depth [2]. Theoretical height of a breaking wave is marked by "~X". Also the maximum speed of the waves is limited by the depth. - The precision is about 5% but there are numerous parameters like wave-heights obtained only approximately by observations. Windspeed on input is limited to 65 knots, other parameters similarly. -
The program has been tested to reproduce data given in refs.[1],[2] and[3], as explained inside the program.
Conversions: 1 knot=0.51 m/s, 1 m/s = 1.94 knots.
[1]Document WMO702.pdf (chap.4) of World Meteorological Organisation.
[2]a) Miche, "Le pouvoir reflechissant des ouvrages maritimes", in Annales des ponts et chaussees, 1951, p.285-319.- b) Also 1944, same journal, eq.(55).
[3]U.S. Coastal Engineering Technical Note CETN-IV-9 by Jane McKee Smith 1997.

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the license or any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ( for more details. If errors are encountered, kindly inform: - Last update 23. dec. 2022.