What did this have to do with surfing? Everything.

As the sport’s popularity rose in the 1970s and ’80s, Brazilians became serious about surfing, but with a few exceptions they didn’t make it big. A large continental shelf in the Atlantic means that there is not a single first-rate “break” along Brazil’s coastline. To be really good, a Brazilian surfer needs to develop proficiency on more than those gutless waves; he needs the storied breaks of Hawaii, Indonesia or Tahiti, which produce large and powerful surf. For decades, it was the rare Brazilian who could afford to travel to such places.

When Brazilian surfers did travel abroad, they usually went without much support, money or technical assistance. They spoke broken English and had little international experience. And there was a culture clash: They developed a reputation as loud, obnoxious and aggressive, heedless of surfing etiquette. This stereotype (still the subject of heated debate) kept them out of favor with dominant surfers, foreign fans and specialized media.

As a country, too, Brazil played fast and loose with the rules. When the demand for surf gear grew in the ’80s, pirated T-shirts, board shorts and wet suits became ubiquitous. Little was done in Brazil to combat this, leaving some of the most powerful chief executives in the business feeling cheated — and less likely to sponsor a Brazilian surfer.

But today’s generation of Brazilian surfers came up during Brazil’s decade of growth, and they have had support along the way. They’ve been going to places like Hawaii regularly and developing into more complete athletes. Someone like Mr. Medina is very much the face of the new Brazilian middle class. His mother worked as a waitress and a maid, among other jobs; his stepfather, a former triathlete, was his coach. The Medinas lived off the income of a surfing goods store. They were Gabriel’s main source of support — financial, emotional and technical — until he signed his first sponsorship deal at 13.

Mr. Medina’s success will presumably help the next generation of young surfers more easily get sponsors. This would be good for Brazil, but it would also be good for the insular, overwhelmingly white world of professional surfing; Brazilian surfing has brought black faces into the sport’s elite circles.