The Potomac River collected dues from local oarsmen yesterday, wreaking havoc with high school and college regattas and causing a collective delay of 4 1/2 hours.

The choppy waters and gusting winds were more cruel to some than others, giving the T. C. Williams third eight an unscheduled swing and contributing to the wreck of Yorktown's new $6,000 Kaschper shell during the scholastic Cherry Blossom Regatta at Potomac Boat Club.

The college crews were more fortunate.The George Washington men's varsity eight caught a rock before the start of its race, but escaped damage. The Duke University women's varsity eight barely avoided a head-on collision with the center support of the Key Bridge.

St. Joseph's of Philadelphia won the boys' varsity eight in open water over Washington-Lee and W-L scored an easy victory in the featured girls' race in the Cherry Blossom after Williams withdrew because of its mishap..

Going off in the early morning, when the conditions were the worst, the Titan third eight caught a wave and a gusting wind flipped the shell.

"In all my years or rowing, I've never seen anything like that," Titan Coach Bob Spousta said. "The boat totallly flipped over and the oars were sticking in the air. It's luckly all the kids could swim.

"We probably could have raced, but to me, the merits of racing were outweighted by our reasons for not racing . . . We wouldn't want to lose someone."

St. Joseph's varsity rowed a steady race, jumping off at 33 strokes per minutes and settling to a 30-31 rating for the remainder of the four-boat race. The St. Joe's lead was two seats over W-L at the midpoint of the mile race before the Philadelphia crew lengthened to slightly more than a boat length by the finish. Marietta of Ohio was another length back in third.

The General girls were left at the start of the girls' varsity race, but overcame Marietta before the midpoint and won by three lengths.

The Yorktown girls, rowing along the Virginia shore en route to the start of the their varsity race, ran across rocks and dug a two-foot gash into the starboard side of their shell before it had even been used in a race.

At Thompson's Water Sports Center, George Washington gave new Coach Joe Carcillo a sweep of the three men's races but not before the regatta, delayed one hour, 45 minutes by the high schools was another two hours, 45 minutes late on its own.

The Colonials triumphed in the exciting three-term men's affair, fighting off a challenge by Washington College of Chestertown, Md., after early competitor Duke faded GW led by a deck after a quarter of the 2,000-meter race and held this advantage until 500 meters were left.

Then, Washington, which had trailed by more than a length before making its move at the halfway point, pulled even with GW before the Colonials rowed away for a three-seat victory with their last 30-40 strokes. Duke died in the wake of a pleasure craft with 500 meters to go and finished another length back.

The Duke women survived a shaky start to edge Washington with the Colonial two lengths back in the only female college competition.

In Pelham, N.Y. Navy's heavyweight crews scored an easy sweep of varsity, junior varsity and freshman races over Columbia in the 22nd meeting for the Maxwell Stevenson Cup at Traverse Island. The Navy varsity trailed early, but broke ahead at the 900-meter point and won by three lengths.

On Weems Creek in Annapolis, the Navy women defeated Virginia in a pair of 800-meter sprints, the first by two seats, then by a length.

Georgetown had a big day on the Cayuga Inlet in Ithaca, N.Y. The women swept the varsity fours, junior varsity eights, and scored a 2 1/2-length triumph over Ithaca in the varsity eights.

The Hoya men captured junior varsity and freshmen heavyweight and a novice four competition among six events. The varsity eight was defeated by Ithaca by more than two lengths.