This Saturday and Sunday, over 300,000 people will crowd Cambridge to cheer on a favorite athletic team. Instead of supporting Harvard or Yale on the football field, however, the crowds will swarm the banks of the Charles River for the Head of the Charles Regatta.

Yale will send all three of its crew teams to Boston this weekend to compete in the 38th annual race. The regatta begins early Saturday morning and ends Sunday with the men’s and women’s varsity eights championships. Billed as the largest two-day rowing event in the world, the 3-mile, single-file, head race will pit the Bulldogs against the world’s most elite crew programs, including the U.S. and German National Teams.

The only way to guarantee a spot in next year’s Head of the Charles is to win this year or finish no more than five percent slower than the winning boat. A lottery is held to fill the remaining spots.

As the defending champions at the Charles, the lightweight men will race two lightweight eights, a lightweight four, and a youth eight — the most entries for any lightweight college team.

“This is what we want to do again, to qualify as many boats as possible for the 2003 regatta so that more Yale lightweight oarsmen will be able to experience the Head of the Charles,” lightweight head coach Andy Card said.

Though the lightweight men return to Boston with a reputation that precedes them, the Bulldogs still believe there is room for improvement.

“We won the lightweight event last year, and the year before that, but we do not have any expectations going into this weekend,” captain Ben Hamilton ’03 said. “We just want to row the best race we can this Sunday and hopefully it will be good enough to win again.”

The heavyweights will race one varsity eight, one varsity four and one youth eight heavyweight this weekend. Because the Head of the Charles is Yale’s second competitive regatta of the season, and because first-year heavyweight head coach John Pescatore had not yet established which rowers would occupy the top boats, this weekend will be the first time that the Bulldogs’ top rowers will all be in the same boat.

“At the Charles I would like the varsity eight to go a lot faster,” Pescatore said.

The regatta this weekend is the most important race Yale will have this fall.

“The Charles is important for us because it is the one event, outside of the league championships in the spring, in which we get to compete with everyone in our league,” Andrew Brennan ’04 said.

For the women’s crew team, who graduated several seniors from last year’s squad, this weekend will be their first true competitive test.

“This week in practice we really focused on improving our technique, particularly getting more power per stroke,” captain Melissa Merritt ’03 said. “We made a lot of gains this week, and it should really pay off this weekend.”

The women, who finished third among colleges, and fifth overall in last year’s competition, are expecting to equal or better their performance. They will race a varsity eight, a varsity four and a freshman four.

The regatta will provide a crowd from start to finish, but women’s crew team head coach Will Porter doesn’t want his team to be distracted by the excitement associated with the prestigious race.

“The fall is a time to check out the competition and gather information,” Porter said. “It’s too early for expectations, my hope is that we perform the way we want to race.”