The graph shows the combination of swells directed at Bob Hall Pier through a typical June. It is based on 1592 NWW3 model predictions since 2006 (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 Bob Hall Pier. In this particular case the best grid node is 24 km away (15 miles).

The rose diagram illustrates the distribution of swell sizes and swell direction, 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 happened only 9% of the time. Green and yellow represent increasing swell sizes and red represents the biggest 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 dominant swell direction, shown by the biggest spokes, was SE (which was the same as the prevailing wind direction). Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Bob Hall Pier and offshore. We combine these with the no surf category of the bar chart. To keep it simple we don't show these in the rose plot. Because wind determines whether or not waves are clean enough to surf at Bob Hall Pier, you can view an alternative image that shows only the swells that were forecast to coincide with glassy or offshore wind conditions. Over an average June, swells large enough to cause surfable waves at Bob Hall Pier run for about 91% of the time.

IMPORTANT: Beta version feature! Swell heights are open water values from NWW3. There is no attempt to model near-shore effects. Coastal wave heights will generally be less, especially if the break does not have unobstructed exposure to the open ocean.