January
30

Surf Science: Swell Direction

MiOla2

Izzy Poulin in the Dominican Republic. Photo by @jake_of_all_trades

In our other Surf Science posts, we’ve covered how waves are made, where and what direction they break, and wind conditions. Now we have to consider where the waves are coming from, swell direction.

Swells come from all different directions (North, South, East, or West), depending on where you are located in the world and where the storm that is generating the swell.  Swell direction is also further forecasted in degrees on a compass. For example, 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).

compass

A quick break down on degrees is:

North Swell (0 Degrees) = Heading South

East Swell (90 Degrees)  = Heading West

South Swell (180 Degrees) = Heading North

West Swell (270 Degrees) = Heading East

Screen Shot 2015-01-27 at 11.42.22 AM

Then we need to consider what direction your beach faces (North, South, East, or West). For example, our home break Tamarindo faces North-West.  The best waves usually are generated from a North or West swell.  These swells typically come from Alaska during the Northern Hemisphere winter at 265°- 310°. If you cross the river mouth here in Tamarindo and surf Playa Grande which faces South-West, the best swells come from the South at 170° – 240°. These swells are usually generated during the Southern Hemisphere winter.

enjoy the ride.aspx

Tamarindo during a North swell. Photo by team rider Kristen Brown.

So what happens if you live in Tamarindo and there is a South swell???  There is potential for the swell to refract and still produce waves in Tamarindo (in general the swell angle needs to be greater than 210°). The waves will be smaller since the swell is not a direct hit to Tamarindo, BUT some waves are better than no waves!  And, at times the swell can be too powerful and direct for Playa Grande, so  more surfable waves happen to be in Tamarindo.

Sound a bit confusing? Don’t worry, just like weather forecasting, surf forecasting can be wrong. Our rule of thumb is to just show up and the beach, paddle out and have some fun!