The rose diagram shows only the swells directed at Shipwrecks - Hyatt Beach that coincided with light winds or offshore conditions over a normal northern hemisphere spring and is based upon 4858 predictions, one every 3 hours. The direction of the spokes show where quality surf generating swell comes from. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. Green and yellow illustrate increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how frequently that size swell was forecast.
The diagram suggests that the dominant swell direction, shown by the largest spokes, was S, whereas the the prevailing wind blows from the E. 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 7% of the time, equivalent to 6 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal northern hemisphere spring but 4% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 4%, equivalent to (4 days). Taking into account the ratio of these swells that coincided with forecast offshore winds we calculate that clean surf can be found at Shipwrecks - Hyatt Beach about 7% of the time and that surf is messed up by onshore wind 14% of the time. This is means that we expect 19 days with waves in a typical northern hemisphere spring, of which 6 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.