Face Height - The measurement of surf and wave heights by the front of the wave from the top of the crest to the low part of the trough in front of the wave. Surfline uses this form of wave measurement.
The steepening shoreward front of a wave, where most waveriding occurs.
A wave state just prior to the wave breaking, when the crest begins to show a little whitewater as the wave face steepens. Most often seen in offshore wind conditions.
The area across the ocean over which a wind with a consistent direction generates waves and sea state. The fetch length is one of the three key elements in the fundamental wave generation formula-along with wind velocity and wind duration-used to determine wave heights and wave periods in a storm or wave generating area.
Really good surf. Also called pumping, or going off.
When there are no waves to surf. Unridable surfing conditions. Some waves also have "flat" sections, which are mushy and powerless.
The white water of a breaking wave and/or the bubbles left over from a breaking wave.
The initial long-period waves that travel faster than the main body of the swell.
When two tropical cyclones rotate about each other. This is caused by the lack of steering winds in the upper atmosphere so the cyclones actually end up affecting each other.