“You should’ve been here yesterday!” We’ve all heard it, and hopefully you’ve had the luxury of saying it, but how do you actually quantify the conditions at your local break? One of the advantages of recording the observational swell data provided by ocean buoys is that it allows us to reference historical reports and plot them over time as well as location.

Having recently moved to Los Angeles from Hawaii, I’m still getting a feel for the region and how swell energy impacts the coast. Compared to my experiences on the North Shore of O‘ahu, the waves in Southern California tend to come off a bit soft. But how soft? How do you measure the relative strength of the two regions?

To satisfy my curiosity I’ve built a monthly wave power almanac, which displays the maximum wave power per month, as well as the average. The background color indicates scale, with white being the least powerful and deep purple being the most powerful. The two stations I’ve chosen to look at are Dana Point in California and Waimea Bay in Hawaii. Let’s begin with the Dana Point buoy.

Dana Point, California - Primary Swell Power (April 2012 - May 2010)

The first month that stands out is September 2011, it’s the lone green block with a maximum of 48. Guess what swell that was (unsure?). While it wasn’t nearly as deadly by the time it crossed the Pacific, the “Code Red” monster from Tahiti is still the most powerful event on the buoy over the past 24 months. April 2012 is actually the second most powerful at 37, likely as a result of the large NW swell that pushed through at the beginning of the month.

Aside from those two, no other month surpasses 30, although there are a few high 20s. The least powerful month was October 2010, which recorded a measly maximum of 8. As we move on to the Waimea Bay buoy, things starts to get a bit more colorful.

Waimea Bay, Hawaii - Primary Swell Power (April 2012 - May 2010)

Let’s start off with July 2011. It had a maximum wave power of 2. Why do you think everyone jumps on their stand-ups and paddleboards on the North Shore during the summer? There’s literally nothing to surf.

It’s an entirely different ocean just six months earlier. January 2011 packs the most mana, with a recorded maximum wave power of 218. That’s over four times more powerful than anything recorded by the Dana Point buoy in the last 24 months. In fact, the average wave power during that month was 30! Definitely a stellar month, as well as a stellar 2010-2011 season for Hawaii.

You’ll also notice that with the Pipe Masters running in December, the ASP has kinda been missing out these last two years. January and February of both 2011 and 2012 have been about twice as powerful as December. Both the Backdoor Shootout and the Volcom Pipe Pro scored ridiculous surf this past year, with the latter actually stopping competition because Pipeline got too big.

Having access to data like this helps put things into perspective and identify those truly special “should’ve been there” moments. It also provides a frame of reference for future conditions, when similar calculations are applied to forecast models. Of course there are plenty of other factors that can influence the quality of the surf, but if the power is there, there’s potential.