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

Overall: 3.7

See all 18 ratings

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Surf Report Feed

Black Rocks Swell Statistics, Autumn: All Swell – Any Wind

The graph illustrates the range of swells directed at Black Rocks over a normal northern hemisphere autumn, based on 8724 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast wind or surf right at the shore so we have chosen the most applicable grid node based on what we know about Black Rocks. In this particular case the best grid node is 35 km away (22 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 represent increasing wave sizes. Very small swells of less than 0.5m (1.5 feet) high are shown in blue. These were forecast only 20% of the time. Green and yellow represent increasing swell sizes and red illustrates the largest swells, greater than >3m (>10ft). In each graph, the area of any colour is proportional to how frequently that size swell happens.

The diagram suggests that the most common swell direction, shown by the largest spokes, was WNW, whereas the the most common wind blows from the SW. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Black Rocks and away from the coast. We combine these with the no surf category of the bar chart. To avoid confusion we don't show these in the rose diagram. Because wind determines whether or not waves are good for surfing at Black Rocks, you can select a similar diagram that shows only the swells that were expected to coincide with glassy or offshore wind conditions. During a typical northern hemisphere autumn, swells large enough to cause clean enough to surf waves at Black Rocks run for about 80% 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.

FEATURE UPDATE: we now show red swell icons for 'open sea' swells that are travelling in an unfavourable direction for the surf break. In places, these swells may still wrap around coastlines and produce smaller waves at some breaks. They are also significant for windsurfers and other water users that tend to venture further off-shore.