Rottnest

Directional graph

The bearing of the arrow indicates the direction of the sea and swell. The point of the arrow indicates the period of the sea and swell.

Historical wave direction graph

The coloured circles indicate the changes in sea and swell direction over time.

Significant wave height graph   

Swell

Swell waves reach the central and southern coasts of Western Australia from distant storms, normally in the Southern Ocean. Unless there is cyclone activity in the North, the same swell patterns are observed to varying heights and at different times along the coast. Swell waves are long and smooth and are generally characterised by a wave period greater than eight seconds.

The wave period is the time between consecutive wave crests.

Sea

Sea waves are generated by local winds and are usually short and choppy. They have shorter wavelengths and periods than swell waves and are generally steeper.

The wave climate at any location can be, and usually is, a combination of sea and swell and is often referred to as the total wave. The near real-time wave data is downloaded from recording sites and graphics created for the web using software developed by Tremarfon Pty Ltd.

Disclaimer, conditions of use and copyright notes

© These images are under copyright to the Western Australian Government. You are not permitted to use these images for whatever reason including placing these images on another web site without prior written agreement from the Department's Coastal Data Centre. 

Please refer to the Department's coastal data disclaimer and further information on copyright and conditions of use..

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