The rose diagram describes the variation of swells directed at Devil s Punch Beverly Beach through a typical September. It is based on 1680 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the coastline so we have chosen the best grid node based on what we know about Devil s Punch Beverly Beach. In the case of Devil s Punch Beverly Beach, the best grid node is 44 km away (27 miles).

The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing but lacks direction information. Five colours represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These occurred only 7% of the time. Green and yellow illustrate increasing swell sizes and red represents highest swells greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how commonly that size swell happens.

The diagram implies that the prevailing swell direction, shown by the largest spokes, was W, whereas the the dominant wind blows from the NW. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Devil s Punch Beverly Beach and offshore. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose graph. Because wind determines whether or not waves are good for surfing at Devil s Punch Beverly Beach, you can load a different image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average September, swells large enough to cause clean enough to surf waves at Devil s Punch Beverly Beach run for about 93% of the time.

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.