The vertical distance from still water level to wave peak (half the height of the wave).
The same as Tube. The hollow part of a breaking wave where there is a gap between the face of the wave and the lip of the wave as it curls over. One of the highlights for any surfer is catching a tube ride.
The features of the sea floor. The measurement of water depth at various places in a body of water.
In fluid dynamics, the Boussinesq equations for ocean waves is an approximation valid for weakly non-linear and fairly long waves. The approximation is named after Joseph Boussinesq, who first derived them in response to the observation by John Scott Russell of the wave of translation (also known as solitary wave or soliton). The Boussinesq equations and Boussinesq-type equations were first introduced and published in 1872.
The first small waves created when the wind blows on the sea.
The rapidity or speed of motion or action or propagation of an ocean surface wave, or other wave on the surface of a liquid.
Moderate local winds form little waves known as chop, or Wind Chop.
A wave that breaks along its entire length at the same time making it unstable for surfing. Closeouts can either be caused by a strong offshore wind or sea floor topography and are also called shutting down.
Swell lines that look like corduroy.
The highest part of the wave (above still water level). Same as the Wave Peak.
CRUMBLE / CRUMBLY WAVES
The lip of waves weakened by onshore wind are said to crumble, unstable for surfing.
DECAY OF WAVES / WAVE DECAY
The decrease in wave height and increase in wavelength of a wave once it is outside the fetch.
When the wave comes into contact with an obstacle or barrier such as a breakwater, the energy of the wave is transmitted along a wave crest. Diffraction is the ‘spreading’ of waves into the sheltered region within the barrier’s geometric shadow.
The Doppler shift or effect, named after Christian Doppler, is the change in frequency and wavelength of a wave for an observer moving relative to the source of the waves.
The area of sea surface where the wind generates the waves/swell. Fetch is one of the key areas in the quality of a swell and the size of the waves.
FULLY DEVELOPED SEA
Waves that have reached the maximum size possible for a fetch, wind speed and wind duration.
Waves that have incredibly smooth faces due to the lack of local wind or a slight offshore wind. Have a look at this picture of a glassy Huntingdon Beach wave.
Waves no longer being affected by the winds that generated them. Waves outside the Fetch.
A Left is a wave that breaks from left to right as you are looking from the beach.
The upper most part of the breaking wave where a surfer will do maneuvers such as a floater.
Smaller than normal tides occurring then the gravitational pull of the Sun and Moon are at right angles to the Earth.
This in surfing terms relates to the wind blowing from the shore. A ground swell mixed with offshore winds makes for cracking surf.
The opposite to offshore. The wind blows toward the beach and as a result the waves lose their shape and crumble.
The highest part of the wave (above still water level) and synonymous with the Crest.
The wave direction at the frequency at which a wave spectrum reaches its maximum.
PEAK PERIOD / WAVE PERIOD
The time taken for consecutive wave crests or wave troughs to pass a given point and the greater the wave period the better the swell.
Wave propagation is any of the ways in which waves travel through space and time, usually with transference of energy.
The tendency of wave crests to become parallel to underwater contours as waves move into shallower waters. Waves moving in shallow waters move more slowly than waves moving in deeper water. Refraction can be seen where waves ‘wrap’ round a point and their direction seems to change.
A Right is a wave that breaks from right to left when viewed from the beach.
SIGNIFICANT WAVE HEIGHT
How significant are your wave heights? You are likely to have seen significant wave height on surf reports. The Significant Wave Height is the average height of the one-third highest waves of a given wave group.
Waves being forced to bunch together as they enter shallower water and slow down.
Larger than normal tides occurring when the gravitational pull of the Sun and Moon are combined in line. The opposite effect to Neap Tides.
The Stokes drift is the difference in end positions, after a predefined amount of time (usually one wave period), as derived from a description in the Lagrangian and Eulerian coordinates. This nonlinear phenomenon is named after George Gabriel Stokes, who derived expressions for this drift in his 1847 study of water waves.
Waves breaking near the shore.
The area from the shore out to where the waves start breaking, and surfers lineup.
The increase and decrease in sea level resulting from the Moon’s and to a lesser extent Sun’s gravitational pull.
The lowest part between two successive waves (or the part between two successive waves below still water level).