Bit of back to basics for many but we know a lot of keen surfers still feel less than confident with understanding swell direction*. We’ve written a little example of reading swell direction on your surf forecast that talks about the importance of this for understanding the surf (there’s plenty more to add – it’s a critical part of the forecast) but before you can even do that you need to get to grips with the terminology. This diagram is a nice illustration to understand the relationship between degrees and the compass points. On MSW we always talk about swell and wind directions as the direction they come FROM. So a South West swell is coming from the South West (and heading to the North East) and you can see from the diagram that the angle would be 225 degrees (numbers on the outside edge). Bear in mind there’s no hard and fast convention on this, most surf forecasters do the same but you will find information using different systems elsewhere on the web.
North Swell (0 Degrees) = Heading South
East Swell (90 Degrees) = Heading West
South Swell (180 Degrees) = Heading North
West Swell (270 Degrees) = Heading East
So back to a MSW forecast – you can see the swell direction arrows (ringed red in this example). These arrows point in the direction the swell is heading TO, in this case TO the South East – so the swell is coming FROM the North West or 315 degrees so we call it a North West swell. To get the precise swell direction from your MSW forecast just hold your mouse over the swell direction arrow and we’ll give you the reading in degrees.
*Same direction convention applies to wind as well as swell.