Sai Wan Beach Surf Stats

The figure illustrates the range of swells directed at Sai Wan Beach through an average April, based on 3360 NWW3 model predictions since 2007 (values every 3 hours). The wave model does not forecast surf and wind right at the coastline so we have chosen the most applicable grid node based on what we know about Sai Wan Beach, and at Sai Wan Beach the best grid node is 17 km away (11 miles). The rose diagram describes the distribution of swell sizes and swell direction, 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 83% of the time. Green and yellow show increasing swell sizes and red illustrates largest 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 ENE, whereas the the most common 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 Sai Wan Beach and out to sea. We combine these with the no surf category of the bar chart. To simplify things we don't show these in the rose graph. Because wind determines whether or not waves are clean enough to surf at Sai Wan Beach, you can load a different image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. In a typical April, swells large enough to cause surfable waves at Sai Wan Beach run for about 3% of the time.

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