Botany Bay Surf Stats

This picture shows the variation of swells directed at Botany Bay through a typical May, based on 3440 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast wind and surf right at the coast so we have chosen the most applicable grid node based on what we know about Botany Bay. In the case of Botany Bay, the best grid node is 16 km away (10 miles). The rose diagram illustrates 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 5% of the time. Green and yellow represent increasing swell sizes and red represents biggest swells greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell happens. The diagram suggests that the dominant swell direction, shown by the biggest spokes, was NE, whereas the the prevailing wind blows from the ESE. Because the wave model grid is away from the coast, sometimes a strong offshore wind blows largest waves away from Botany Bay and out to sea. We lump these in with the no surf category of the bar chart. To keep it simple we don't show these in the rose graph. Because wind determines whether or not waves are surfable at Botany Bay, 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 May, swells large enough to cause good for surfing waves at Botany Bay run for about 95% of the time.

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