How to use Surfline's Advanced Charts

There are few things that illicit the visceral reaction in surfers that a good ol’ fashioned ‘purple blob’ does, when we see said blob in our area of interest. We know it’s going to be pumping sometime in the not too distant future, although the exact when and where is usually a little fuzzy.

In this tutorial we’re going to teach you how to better understand and interpret our significant wave height charts (purple blobs) and some of the other advanced charts in the Surfline repertoire, so that the fuzziness comes into better focus.

Step one is the location of our advanced charts section. From any forecast page click on the ‘Charts’ section at the top of the page. While there are several different types of advanced charts that are available from this new page, the default product is the significant wave height chart, so we’ll primarily discuss that popular chart in this feature.

The significant wave height chart- or purple blob chart- displays wave heights over an area of interest in the ocean or large body of water (including the Great Lakes). The colors on the map/chart can be deciphered using the scale at the right bottom of the image, which indicates wave height in feet. The purple colors are the most popular amongst surfers as they represent larger waves heights and, potentially, larger surf for your area of interest. The white directional arrows indicate the direction the waves/swell are traveling toward, so you’ll know if that purple blob is heading your way or elsewhere.

To change the time in these charts mouse over the light and dark gray boxes or use the play/pause buttons at the top of the image. 


Other charts are also listed on the left hand rail. These charts all have the same functionality as the significant wave height chart described above, although the data displayed is obviously a little different. Happy charting and we’re hopeful that this helps you score bigger and better surf!

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