Mechanics of the Gnarliest Dungeons in a Decade

Tony Butt

by on

Updated 118d ago

The ‘Cape of Storms’ in South Africa recently witnessed one of the cleanest, longest-period, big swells in living memory. Here’s what happened.

The Cape Peninsula sticks right out into the Southern Ocean, close to the Roaring Forties. It is constantly battered by raw, unfiltered swell and strong local winds. The big, gnarly surf on offer is some of the best in the world, but you often have to put up with less-than-perfect conditions.

On Sunday July 8, however, things were different. A huge, super-clean, lined-up swell arrived from the west, groomed by light northeast winds. It looked more like a giant version of Indonesia than the Cape of Storms. A lot of people around here were saying that they’d never in their whole life seen a swell as big and perfect as that.

Speaking to MSW, Matt Bromley who was out charging Dungeons as this well hit, taking his 63-year-old dad John along for his first swing at the big wave hell pit said: “I paddled out into the line up and a solid one came my way. I put my head down and air -dropped into a steep one, narrowly escaping the lip and riding into the channel to my wife shaking on the boat. 

“It turned into what most were saying is the best day in the last decade. Glassy, thick chunks of water marched in and unloaded across the reef, spitting their guts out into the channel.

Juri Muller looking to do some cave diving.

Juri Muller looking to do some cave diving.

© 2018 - Grant Scholtz

“The waves were missing the outside ledge and focusing all the energy close in on the reef, making it almost impossible to paddle the real gems. Set after set came in, and bru's would spin to go but last second have to pull back, as the swell sucked underneath them with boils and steps coming up the face. The takeoffs were super intimidating and most of the good ones went unridden. I surfed for 8 hours and only managed around 8 waves the whole day. Most of the time was spent watching the biggest and most perfect barrels I've ever seen out there.

It turned into what most were saying is the best day in the last decade

“I tried for so many good ones, and last minute having to crank on the breaks, as the wave sucked out totally vertical under me.

“A sheep farmer from up the east coast, Juri Muller, and old dog Jake Kolnick, were probably the stand outs from the session, however Juri got kaned and snapped his board and Jake got lipped on a wave that imitated Shipsterns, bursting his ear drum and getting concussed.

“Everyone was frothing on the session but had their tails between the legs. Big shout out to my dad, John Bromley, who paddled out to watch and then decided to paddle into his first wave at Dungeons at 63.”

Jake Kolnick's Shipstern'ss impersonation which resulted in a concussion and burst ear drum.

Jake Kolnick's Shipstern'ss impersonation which resulted in a concussion and burst ear drum.

© 2018 - Grant Scholtz

Almost a week before it happened, I could see things lining up on the charts. Around Tuesday 3, a giant storm was forming about 1,500 miles southwest of Buenos Aires, with a strong fetch on its northern flank. The storm persisted for about three days, tracking slowly west to the middle of the South Atlantic. The continuous storm-force westerly winds and dynamic fetch (see my article HERE) generated a large, long-period swell heading straight towards Cape Town. The storm then completely dissipated before getting anywhere near the coast.

An area of weak pressure gradients extending at least 1,000 miles out from the coast persisted all the way through until the swell arrived on the Sunday. This meant that the swell remained completely clean and free of any interference from locally-generated short-period swells, windseas or residual bumpiness.

Jake Kolnick takes in the sights.

Jake Kolnick takes in the sights.

© 2018 - Grant Scholtz

When the swell arrived it was significantly bigger than most of us thought it was going to be. The forecasted significant wave height was just over three metres. Admittedly, with periods of 18 secs or more and a direction more west than usual, I knew that Sunset Reef would be much bigger than that. And, yes, it was huge. But other spots like the Outer Kom, Crayfish Factory and, of course, Dungeons, were also much bigger than expected.

As Bromley said: “The first wave I saw struck fear into me, as I had no idea it was going to be this gnarly. I had mentally prepared for like 15ft waves, but this was another story.”

I don’t know why, but the significant wave height (the average of the highest third of the waves) measured by the Cape Point wave buoy, about 7 km off the coast, was about 30% bigger than the forecasted wave heights, particularly around midday. Also, the peaks measured by the buoy were almost twice that size. Those peaks, sometimes almost hitting seven metres, would have corresponded with the monster sets that came through about every 15 minutes.

Brom dog on an absolute monster.

Brom dog on an absolute monster.

© 2018 - Grant Scholtz

In summary, the Cape Swell of July 8 2018 was really special, and maybe something that won’t happen again for a long time. We all knew that it was going to be an exceptional swell, but nobody was really expecting it to be so big and clean. Here on the tip of Africa, you need to be prepared for anything.

Additional reporting by Jason Lock.