The colossal 80-foot waves of Nazaré challenge even professional big-wave surfers

When you search for the world records for the largest waves ever surfed, a clear pattern emerges. Six of the top seven waves, and seven of the top ten, are all from one place: Praia do Norte in Nazaré, Portugal.

What makes those Nazaré, Portugal waves so special? Is it just one surfer on a Portuguese beach, constantly breaking records with a crew of Guinness World Records enthusiasts?

Not at all — in fact, as of 2023, each of the nine largest waves was surfed by a different individual. The true reason behind these colossal waves is tied to the distinct underwater terrain just off the coast of Nazaré.

Average Waves vs. Truly Massive Waves

Ocean waves are created when something disrupts the water. In a swimming pool, this might occur when the neighborhood bully does a big cannonball off the high dive. In the open ocean, waves are often the result of a wake from a speedboat driven by someone in a midlife crisis.

In a more serious context, tsunamis — massive waves triggered by underwater earthquakes — literally shake the ocean. But most of the time, it's the wind that creates the waves crashing on the shore. Yes, the powerful gusts of wind somewhere out at sea are what set the waves in motion.

Creating the gigantic waves ridden by the likes of Maya Gabeira, Sebastian Steudtner, and Garrett McNamara at Nazaré involves more than just wind. The unique topography of the ocean floor plays a crucial role in generating these monstrous waves.

The typical, everyday wave crashes against the shore when water runs out of space. As the water approaches the beach, the land pushes the water upwards, causing it to curl and eventually break under gravity’s downward force. This same phenomenon occurs at Nazaré, but on a far grander scale. This is due to the unique characteristics of the coastline here, which is no ordinary beach.

The massive waves at Nazaré’s Praia do Norte result from four key factors:

What Makes Nazaré Unique

At first glance, Nazaré appears to be a typical European beach, with its sandy shores and relatively calm waters for most of the year. On days when the offshore conditions are peaceful, you can enjoy a very ordinary beach experience at Nazaré.

Nazaré Canyon

Just off the coast, the ocean floor reveals something extraordinary. Nestled beneath the waves lies the Nazaré Canyon, an underwater trench stretching 140 miles (230 kilometers) in length and plunging to depths of up to 16,000 feet (4,877 meters). It is this remarkable canyon that transforms typical waves into colossal giants.

As waves approach the Portuguese coastline, the Nazaré Canyon divides them into two. One portion of the water sinks into the canyon, continuing its forward motion, while the other part pushes ahead, creating waves similar to those that form where land meets the sea.

The Nazaré Canyon reaches its end near Praia do Norte (North Beach) in Nazaré. Here, the incoming water from the canyon is forced upward as it races toward the shore. This surge of water combines with the wave at the surface, creating a towering double wave that is notably larger than usual.

Constructive Interference

As Edward Santilli, a physics professor at Thomas Jefferson University, puts it: "Usually, waves interact in a random manner and don't result in anything remarkable. However, if they meet at the right angle, they can either cancel each other out (destructive interference) or combine to form a larger wave (constructive interference)."

Nazaré is a prime example of constructive interference in action. The offshore canyon there amplifies this effect, making it a powerful force at Praia do Norte in Nazaré.

"Waves in shallow water move more slowly than those in deeper waters," Santilli explains. "As waves approach the shore, they slow down. But this results in the front of the wave being in shallower waters than the back, which causes the trailing parts to catch up with the front. This process narrows the wave, but all the water still needs to go somewhere, so it rises — making the wave taller."

Vaulting to Legendary Heights

Another factor that boosts the size of Nazaré's waves is the current that runs along the coastline. The offshore canyon causes the massive waves at Nazaré to originate from the southwest, and as they break at Praia do Norte, they move toward the north and east.

In ideal conditions for big waves, Nazaré experiences light northwest winds that push water southward along the shore, creating a kind of barrier. As the massive waves roll in from the southwest, they collide with this north-to-south running current.

The larger, more powerful waves from the southwest leap over the shoreline current, much like a car bouncing over a speed bump at high speed. This final leap is what gives Nazaré's waves their towering height.

Big Waves Season

If you take a look at the list of world record-breaking waves, you'll spot a common pattern: they were all ridden in late fall or early winter. This is because these seasons bring the most powerful storms in the North Atlantic Ocean.

Keep in mind that wind is the driving force behind nearly all ocean waves. However, for large waves to form, these wind events must occur far out at sea, well offshore.

The most powerful winter storms in the Atlantic Ocean occur hundreds of miles off the coast of Portugal. Over time, these storms generate waves that travel eastward toward the Portuguese coast, gaining speed as they move. When these waves pass over Nazaré Canyon, they accelerate even more due to the canyon's lack of barriers to absorb their energy.

While this phenomenon unfolds at sea, the best days for surfing also feature a gentle northwest wind, which pushes a current of water southward along Nazaré's coast. This current acts as a final water barrier that amplifies the waves, causing them to rise even higher than they otherwise would.

The perfect conditions for towering waves at Nazaré require winter storms to be positioned far out at sea, not near the beach. While this occurs, Praia do Norte benefits from a mild northwest wind, providing the ideal setup for wave heights to reach their peak.

When you examine photos and videos of record-breaking surf days, you'll notice the absence of an intense storm overhead. In fact, if the storm were directly above Nazaré, it would disrupt the perfect surf conditions.