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Mahai'ula Bay ratings
Quality on a good day: 3.0
Consistency of Surf: 3.0
Difficulty Level: 1.0
Crowds: 3.0

Overall: 3.2

See all 18 ratings

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Surf Report Feed

Mahai'ula Bay Swell Statistics, October: All Swell – Any Wind

This image shows the combination of swells directed at Mahai'ula Bay through a typical October, based on 2976 NWW3 model predictions since 2006 (values every 3 hours). The wave model does not forecast surf and wind right at the shore so we have chosen the optimum grid node based on what we know about Mahai'ula Bay, and at Mahai'ula Bay the best grid node is 24 km away (15 miles).

The rose diagram illustrates the distribution of swell directions and swell sizes, while the graph at the bottom shows the same thing but 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 75% of the time. Green and yellow illustrate increasing swell sizes and red illustrates the biggest swells, greater than >3m (>10ft). In either graph, the area of any colour is proportional to how frequently that size swell happens.

The diagram suggests that the dominant swell direction, shown by the largest spokes, was NW, whereas the the prevailing wind blows from the NNE. Because the wave model grid is offshore, sometimes a strong offshore wind blows largest waves away from Mahai'ula Bay and away from the coast. 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 surfable at Mahai'ula Bay, you can view an alternative image that shows only the swells that were expected to coincide with glassy or offshore wind conditions. Over an average October, swells large enough to cause good for surfing waves at Mahai'ula Bay run for about 7% 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.