Martin's Bay Surf Stats

The graph describes the range of swells directed at Martin's Bay over a normal July. It is based on 3472 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 Martin's Bay, and at Martin's Bay the best grid node is 33 km away (21 miles). The rose diagram shows the distribution of swell sizes and directions, while the graph at the bottom shows the same thing without 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 0.8% of the time. Green and yellow illustrate increasing swell sizes and highest swells greater than >3m (>10ft) are shown in red. In each graph, the area of any colour is proportional to how commonly that size swell happens. The diagram implies that the dominant swell direction, shown by the largest spokes, was ENE, whereas the the dominant wind blows from the E. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Martin's Bay and offshore. We combine 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 good for surfing at Martin's Bay, you can select a similar diagram that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. During a typical July, swells large enough to cause clean enough to surf waves at Martin's Bay run for about 99% of the time.

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