Down the Schuylkill they stroked, six sculls at a time, covering 1,500 meters as fast as they could along a river made faster by the rain.

The 85th annual Stotesbury Cup competition, billed as the biggest high school regatta in the world, began Friday morning with qualifying time trials for about 5,000 athletes from 176 high schools on 868 boats.

Starting just before the Strawberry Mansion Bridge and finishing a little past the grandstands near the Columbia Bridge, the heats began with the boys' freshman eight and ended with the boys' senior eight.

By 4 p.m., eight hours after the event began, the crews with the top 18 or 12 fastest times, depending on the event, had qualified for the semifinals - some of which were held Friday, and the rest Saturday before the finals.

The top two or three places, depending on the event, advanced to the finals.

As in boxing, the heavyweights drew lots of interest from an estimated 15,000 to 20,000 spectators.

The boys' senior eight crew with the best time in its heat was St. Joseph's Prep. St. Andrew's (Del.) was a close second. Radnor and Mount St. Joseph came in one-two for the girls.

St. Joseph's Prep crossed the finish line in 4 minutes, 5.91 seconds. St. Andrew's was clocked in 4:06.25.

"There will be a barnburner of a finish [Saturday]" in the semifinals and finals, Prep coach Jim Glavin said. "We knew that we'd be close to St. Andrew's."

St. Andrew's, which had been undefeated before Friday, beat the Hawks at the St. Andrew's Invitational earlier in the season.

"They beat us by 1.3 seconds," Prep fifth seat John McGrorty said of the invitational competition. "Today we won by three-tenths of a second. We've got two more races to go."

McGrorty was joined by coxswain Lou Lombardi, Dean Hill, Zac Munsell, A.J. Abell, Kevin McHale, Steve Markham, Dan Henry, and bow Chris Mulvey.

Among the girls, Radnor was clocked in 4:45.07, and Mount St. Joseph finished in 4:46.69. The two teams have been flip-flopping wins the last two weeks, Radnor coach Megan Biging said.

"I expected them to qualify and I'm pleased with the time," Biging said of her crew, which consisted of coxswain Sophie Faude, Kendall Chapin, Chandler Lally, Alli Webster, Lexie Katz, Sophia Blair, Emma Burke, Hannah Edelmann, and bow Kirsten Fitch.

The varsity eight teams with the top two times get to race Saturday in Lane 3, the calmest of the six lanes, and the times should continue to be fast. And that's good news to the Mount St. Joseph crew of coxswain Maggie Rush, Dana Lerro, Meredith Bracken, Katie O'Connell, Darian DiCianno, Rose Ehrlich, Julie McGlynn, Katie Casebeer, and bow Emily Carbone.

"Lane 3 is a great place to be," Mount St. Joseph coach Meg Kennedy said. "It's great to be in fast water."

The Hawks also had the best time in the boys' freshman eight semifinals (4:34.14), and the Radnor girls' freshman eight also posted a top time (5:06.14).

Conestoga had a good day. The Pioneers in the semifinals had the best time in the girls' freshman quad (5:31.14), the girls' junior quad (5:18.38), and the boys' junior quad (4:38.73).

They also qualified for the finals in the girls' junior double and the boys' freshman quad.

Malvern Prep advanced in the boys' junior double, the boys' lightweight double, and the boys' freshman quad.