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 summer. It is based on 5066 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 show increasing swell sizes and red illustrates the highest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell was forecast.
The diagram indicates that the most common swell direction, shown by the biggest spokes, was S, whereas the the dominant wind blows from the ENE. 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 9% of the time, equivalent to 8 days. Open sea swells exceeding >3m (>10ft) are unlikely to occur in a normal northern hemisphere summer but 7% of the time you can expect swell in the range 1.3-2m (4-6.5ft) 7%, equivalent to (6 days). Taking into account the proportion of these swells that coincided with forecast offshore winds we estimate that clean surf can be found at Shipwrecks - Hyatt Beach about 9% of the time and that surf is spoilt by onshore wind 36% of the time. This is means that we expect 41 days with waves in a typical northern hemisphere summer, of which 8 days should be surfable.
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.