Friday, February 12, 2010

Maverick’s the Surf Break…and a mini-contest forecast

In case you hadn’t heard…they are running the Mavericks contest tomorrow and it is going to be webcast all over everything, which is cool, but there is also going to be some decent surf in Socal too so I don’t think I am going to spend much time watching it live.

Since Maverick’s is a pretty unique wave I thought I would throw together a quick little look at the underwater mechanics that goes into the wave’s formation…and put together a little forecast on what the surf will likely be doing while the contest is running.

So this is NOAA Chart of Pillar Point (up in Half Moon Bay)…I layered some pretty colors on the chart so that we can get a quicker look at the various water depths. In this case darker colors represent deeper water and lighter colors shallower water.

As you can see there is a lot going on underneath the water at Mav’s…basically the dry part of Pillar Point is just part of a much bigger undersea ridge. In the red box is the area that basically defines Maverick’s wave shape…with the most notable feature being the shallow protrusion that pushes off to the W-WSW just below the Pillar Point headland. Here is a closer look at the highlighted region.

As swell approaches Mav’s…in this case a long-period W-NW swell…its energy actually starts to feel the seafloor quite a bit further out to sea (off to the west of this chart and out by the Farallon Islands). As the swells energy starts to hit the sea floor it begins to refract, which is a process where parts of the swell begin to slow down due to friction and eventually bend toward shallower water. This refraction is one of the reasons that Mav’s can even break properly on the steeper angled WNW-NW swells…the swell that should hit the reef at a bit of an oblique angle is pulled around from deeper water and eventually makes a final sort of hook as it loads up on the reef.

What is sort of crazy, and this is sort of a nerd alert, is that Mav’s will work on the medium-long period WNW-NW swells but as the swell-period shortens up the refraction occurs at much shallower water depths and doesn’t let the swells energy hit and wrap the way it does on long-period ones. BUT as the swell direction drops to more westerly angles the swell doesn’t need as much refraction to hit the reef the “right” way and so the break will work just as well on a short-medium period W swell as it might on an longer-period WNW-NW swell.

Anyway… we all know, at some level…sometimes instinctually, that waves break better when they have some sort of fast transition from deep to shallow water and that the final shape of the wave is determined by the shape of the seafloor…just think about your local sandbar for a second and how it behaves when there are deep holes in it. So I am pretty sure that it is no surprise to you guys that Maverick’s does the same thing just on a massive scale.

Here is the forecast for the contest tomorrow…

The new W-NW swell (270-300) is already showing along the Northern Central Coasts (and even on the outer Socal Buoys) this afternoon. Right now the Point Reyes buoy is running about 12-13’ at about 18-20 seconds and there is a larger lump of swell energy that will be arriving overnight into Saturday.

On Saturday…the W-NW’er will peak with nearly 15-16’ of deepwater swell with periods right around the 15-17 second range. Mav’s can take the energy in those sort of swell periods and really use it to jack up wave heights…easily pushing the face size to 1.5-times the deepwater height and nearly 2- to 3-times in extreme cases. So from a “face-size” perspective the contest will have plenty of 15-20’ faces with some bombs nearing 25-30’…maybe bigger if the swell really comes in full strength. Those sort of sizes are right on the edge of not really being a paddle-in wave…so hopefully it won’t push the envelop so much that they pull the plug on the event. Winds look good for Saturday too…N-NE around 10-15 knots…but possibly some patchy fog at times, yeah that sounds fun…25’ mavs with partial visibility…good times.

Anyhoo…just thought you guys might be interested in some of the funkiness that makes Mav’s work.

And I think that you will be able to find all sorts of links to watch the webcast of the contest here…

1 comment:

Anonymous said...

Years ago when Mavs was first being surfed (that is, by others rather than just Jeff Clark), I was eating at a local SC restaurant with my wife.

Our server was a surfer, and we got to talking about surfing, Mavs, etc. He pulled out his ace and mentioned he had 'paddled out'. Now, mind you, he confessed he didn't catch any real waves (just leftovers), but had actually been out there during a swell.

The one thing he said that has always stuck with me was his description of just how intense & crazy it was. Something about how the bottom drops out of these huge peaks and the whole thing cascades over into the trench.

I think it was the next year I got to watch from the cliffs. It really is a freaky place - much, much hairier than Waimea or other big wave spots.