Surfing in Portugal: The day of the Nazaré rogue wave

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Satellite image of October 29, 2020: sediments and white water

Photo: NASA Earth Observatory

It was an extraordinary day, as António Laureano recognized immediately when he looked at the sea off Nazaré in the morning.

The waves in front of the small, red lighthouse that adorns the São Miguel Acanjo fortress above the cliffs were particularly high that day and broke particularly far from the coast, he says.

Laureano, who has been surfing since he was a toddler, grabbed his board and let himself be towed onto the Atlantic on a jet ski.

He was confident but at the same time a little scared when he saw the giant waves rolling towards Praia do Norte that day, the Portuguese later said of the moment of glory.

During the last wave of his surf session, he immediately felt the exceptionally high speed with which he glided down the giant breaker.

The spectators at the lighthouse screamed, seeing a tiny figure against a huge wall of water.

If his mother had seen him doing it, she would probably have had a heart attack, says the surfer, who was just 18 at the time.

In contrast to big wave surfing heroes such as the Americans Laird Hamilton or Garrett McNamara, who only put the town of Nazaré on the global surfing map a few years ago, Laureano is rather slight in stature.

The fact that he is now named together with the greats of his sport is largely due to October 29, 2020. If the height of the monster wave of more than 101 feet, around 31 meters, is confirmed, that would be a new record, the 80 feet wave (more than 24 meters) of the Brazilian Rodrigo Koxa from 2017.

Its great wave also rolled ashore in Nazaré.

On an average day of the season, the Nazaré waves reach an average of 15 meters in front of the north beach.

On a really good one, the masses of water pile up more than 20 meters high.

The place between Lisbon and Porto is now considered a Mecca for fans of particularly gigantic waves and, at least in terms of the number of records set, surpasses legendary spots such as Mavericks in California, Jaws on Maui or Teahupoo off Tahiti.

But did the water really rise as high as António Laureano says at the end of October 2020?

Measuring wave heights for supposed surfing records is a complicated matter.

The World Surf League, which checks the height of the monster breakers based on videos and photos and has to officially recognize them before they can be entered in the Guinness Book of Records, has published a 17-page document.

Koxas is still at the top of the list of the greatest measured wave rides.

But there is another way of approaching the question of whether the conditions on October 29th were really that good: with the help of satellite images.

The two images, both taken by NASA's Landsat 8 earth observation satellite, reveal clear differences in the water off the coast.

The picture on the left is from the supposed record day, the picture on the right shows a rather calm day at the beginning of February this year.

Both images show the foaming white water along the shoreline as the waves break and roll in on the beach.

Comparing the images shows that October 2020 was much wilder in the coastal waters.

White foam edges can also be seen on the sea.

According to the oceanographer José da Silva from the University of Porto, they occur when two different currents meet at the sea surface.

According to the data, on Laureano's big day, the waves were more than six meters high out at sea - that is, in the phase before they pile up and break near the coast and become interesting for surfers.

The time interval between the individual waves is given as around 17 seconds.

In February, however, the wave height off the coast was only about two meters with a wave period of eleven seconds.

None of this provides any precise indications of the height of the wave that Laureano surfed down.

But it confirms that there was a lot going on in the sea at the time.

The weather situation also speaks for very high waves: In October, hurricane Epsilon raged across the Atlantic.

The foothills of the category 3 storm and a low-pressure area near Greenland probably also reached the west coast of Portugal and brought high swell with them.

In general, however, the special topographical formations of the seabed off Nazaré favor the formation of the big waves.

A more than 200 km long and up to 5000 meters deep undersea gorge extends almost directly to the coast.

This formation, in which the seabed rises rapidly over a relatively small area, bundles the current like a channel.

The water increases in height, while the wavelength decreases.

In addition, a second current from a different direction meets these water movements.

When they overlap, it increases the power of the water even more in perfect conditions and makes the waves even bigger.

However, Laureano does not only want to rely on circumstantial evidence for his record proof.

He worked with scientists from the University of Lisbon, who measured his wave and came up with a height of 31 meters.

To do this, the researchers led by Miguel Moreira used software that uses the size of the surfer as a scale reference and defines the highest and lowest points of the wave.

However, this is not easy, because waves are subject to dynamic movements, so the size and angle of the water wall is constantly changing.

But the researchers are certain that they have never measured a larger wave, they report in »Surfing Today«.

joe