Cuba made an auspicious debut today in water polo competition, thrashing a fair Brazilian team, 19-8, and inspiring its supporters to repeated chants of "Cu-ba, Cu-ba."

An hour later the western hemisphere's other water polo power, the United States, proved even more impressive. The United States forged a 6-1 lead in the first period and went on to humiliate Canada, 17-5.

"We don't go to Europe every day, so we've used the important competitions like the Fina Cup (where the U.S. was fifth) to sort our players out," said U.S. Coach Monte Nitzkowski. "Now we're just about set for our run at the Olympic Games."

Surveying the packed stands at the outdoor Piscinas la Rinconada and the lush vegetation that covered the hills beyond them, Nitzkowski said, "I'm surprised so many people found their way out here. It looked like California until I got close. Then it seemed more like a jungle."

It was a jungle in the water, too, until the Canadians lost heart. Eight fouls were whistled against Canada in the first 35 seconds, but Terry Schroeder still managed to give the United States the lead a moment before the 35-second shooting limit expired.

It was Schroeder, the hole setter in front of the opposition's goal, who bore the brunt of the foul play, a calculated part of water polo strategy, but he ignored the intimidation to become the game's only three-goal scorer.

The referees should have a tougher job on Monday, when the U.S. plays Cuba. In 1975, after the U.S. defeated Cuba at Mexico City, goalie Steve Hamann was showering when a Cuban player approached him. Hamann held out his hand, thinking the Cuban was about to offer congratulations. Instead, the Cuban broke his jaw.