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Black Rocks Jetty ratings
Quality on a good day: 2.0
Consistency of Surf: 5.0
Difficulty Level: 4.0
Crowds: 3.0

Overall: 3.7

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Surf Report Feed

Black Rocks Jetty Swell Statistics, Summer: All Swell – Any Wind

The figure illustrates the combination of swells directed at Black Rocks Jetty through an average southern hemisphere summer and is based upon 8485 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind and surf right at the coastline so we have chosen the most applicable grid node based on what we know about Black Rocks Jetty, and at Black Rocks Jetty the best grid node is 24 km away (15 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 14% of the time. Green and yellow show increasing swell sizes and red shows largest swells greater than >3m (>10ft). In either graph, 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 SSW, whereas the the most common wind blows from the E. Because the wave model grid is out to sea, sometimes a strong offshore wind blows largest waves away from Black Rocks Jetty and offshore. 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 plot. Because wind determines whether or not waves are clean enough to surf at Black Rocks Jetty, you can view an alternative image that shows only the swells that were predicted to coincide with glassy or offshore wind conditions. In a typical southern hemisphere summer, swells large enough to cause surfable waves at Black Rocks Jetty run for about 86% 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.