But Ms. Gabeira moved to Nazaré in 2016 and kept training. This winter, when the waves at the notoriously difficult surf spot are at their largest, was the first season she felt fully recovered, she said.

On that Jan. 18, after realizing she had probably surfed the biggest wave of her life, she asked Miguel Moreira, a professor at the University of Lisbon’s Department of Sport and Health, to measure it. But for it to be an official record, Ms. Gabeira needed the World Surf League to certify it.

She flew to the league’s headquarters in Los Angeles to ask for its support, but grew frustrated after many months with no answer, she said. The organization did not immediately reply to a request for comment.

In August, Ms. Gabeira started a petition on change.org asking fans to support the request.

“There are definitely some people who don’t like the idea of women surfing the biggest waves,” she wrote. “Perhaps I haven’t been able to scream loud enough?”

It worked.

The award ceremony on Monday happened by a lighthouse in Nazaré, overlooking the giant waves. (The record for the largest wave surfed by a man is also held by a Brazilian, Rodrigo Koxa, who rode an 80-foot monster in Nazaré.)

Ms. Gabeira hopes her feat will serve as inspiration not only to surfers like her but also to all women who are trying to get recognition for their work.

“It’s important to widen our possibilities,” she said. “Where the space for women doesn’t yet exist, it must be created.”