This image shows only the swells directed at Bedruthan Steps that coincided with light winds or offshore conditions through a typical June. It is based on 1594 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. Green and yellow illustrate increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens.
The diagram indicates that the prevailing swell direction, shown by the biggest spokes, was WSW (which was the same as the dominant wind direction). The chart at the bottom shows the same thing but without direction information. For example, swells larger than 1.5 feet (0.5m) coincided with good wind conditions 6% of the time, equivalent to 2 days. Open sea swells exceeding >3m (>10ft) are unlikely to arise in a normal June but 5% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 5%, equivalent to (2 days). Taking into account the proportion of these swells that coincided with forecast offshore winds, and given the fact that Bedruthan Steps is slightly protected from open water swells, we estimate that clean surf can be found at Bedruthan Steps about 6% of the time and that surf is blown out by onshore wind 41% of the time. This is means that we expect 14 days with waves in a typical June, of which 2 days should be clean enough to surf.
IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.