Nettley Bay Reefs Surf Stats

This picture illustrates the combination of swells directed at Nettley Bay Reefs through a typical October and is based upon 2976 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the shore so we have chosen the optimum grid node based on what we know about Nettley Bay Reefs. In this particular case the best grid node is 13 km away (8 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 show increasing wave sizes. The smallest swells, less than 0.5m (1.5 feet), high are coloured blue. These happened only 1.4% of the time. Green and yellow illustrate increasing swell sizes and red shows the largest swells, greater than >3m (>10ft). In both graphs, the area of any colour is proportional to how often that size swell occurs. The diagram indicates that the dominant swell direction, shown by the longest spokes, was WSW, whereas the the most common wind blows from the W. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Nettley Bay Reefs and away from the coast. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Nettley Bay Reefs, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause surfable waves at Nettley Bay Reefs run for about 99% of the time.

read more