Sai Wan Beach Surf Stats

The graph shows the range of swells directed at Sai Wan Beach through an average November. It is based on 3347 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 most applicable grid node based on what we know about Sai Wan Beach. In the case of Sai Wan Beach, the best grid node is 17 km away (11 miles). The rose diagram shows the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but lacks direction information. Five colours illustrate increasing wave sizes. Blue shows the smallest swells, less that 0.5m (1.5 feet) high. These were forecast only 75% of the time. Green and yellow show increasing swell sizes and red represents the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how often that size swell happens. The diagram indicates that the most common swell direction, shown by the biggest spokes, was ENE, whereas the the prevailing wind blows from the NE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Sai Wan Beach and away from the coast. We group these with the no surf category of the bar chart. To simplify things we don't show these in the rose plot. Because wind determines whether or not waves are surfable at Sai Wan Beach, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical November, swells large enough to cause good for surfing waves at Sai Wan Beach run for about 12% of the time.

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