The picture below shows the effects of the Ahipara headland on the waves wrapping into the Shipwreck Bay points. From an offshore wave angle of SW, the waves wrap around until their crests are aligned almost W-E (wave angle ~ N) at the points, showing why offshore winds on the Shipwreck points need to come out of the SW. The picture also shows more wave energy (bigger waves) hitting the outside points. The reduction in wave height on the inside points is due to the energy of the waves being used up during refraction around the headland. The site location used by Swellmap is right at the inside point, not miles offshore like other marine forecast providers. We take into account the shape of the seafloor offshore from Shipwreck Bay to provide detailed forecasts at the actual surf and marine spots.


The picture illustrates the spatial scale used in some of the modeling by MetOcean Solutions and released by Swellmap.com