The annual Stotesbury Cup Regatta is scheduled for tomorrow and Saturday on the Schuylkill, and this year's event is expected to feature 5,260 athletes, not including alternates, and 856 boats from 180 schools from as far away as Florida, Texas, Michigan, Ontario, and Massachusetts.

Races in 30 events for boys and girls ranging from the single scull to the varsity eight with coxswain will be decided. The regatta, in its 83d year, is billed as the world's oldest and largest high school rowing competition.

Qualifying time trials are scheduled to begin at 8 a.m. tomorrow. Semifinals are set for late tomorrow afternoon and early Saturday morning, beginning at 8. The finals will begin Saturday at 12:40 p.m.

St. Joseph's Prep won the boys' varsity eight last year, and Bishop Eustace won the girls' varsity eight.