Andy Sudduth, an also-ran in the Olympic Games in Seoul last month, won the men's championship singles for the fifth consecutive year yesterday in the 24th annual Head of the Charles Regatta.

Sudduth, a one-time Harvard star now a computer programmer at his alma mater, was timed in 19 minutes, 2.82 seconds on a winding, wind-whipped three-mile course on the Charles River.

Greg Walker of the Detroit Boat Club was second in 19:12.18, followed by Ron Smith, Sudduth's Boston Rowing Center teammate and a member of the U.S. Olympic eightoared crew, in 19:14.42.

More than 3500 men and women competed in 16 events in the regatta billed as the world's biggest single day rowing event. However, records stood up because of a 15-25 mph headwind, which turned into a crosswind on some turns, on the upstream course.

Ann Marden, the Olympic single scull silver medalist from nearby Concord, won the women's championship singles for the third year in a row.

Marden, employed in a London brokerage and rowing for the Thames Tradesmen R.C., was clocked in 20:46.17, defeating Gretchen Weimer of Buffalo, N.Y., by more than one minute. Weimer's time was 21:50.80.

"I just came over for the weekend," said Marden, who flew to Boston Saturday and returned to London immediately after the race. "I wouldn't miss this for anything."

All boats raced against the clock, with starting times computerized.

The Penn A.C., with four members of the U.S. Olympic silver medal boat, won the championship eights in 15:15.31 as the Ridley Graduate B.C. of Canada did not compete after dominating the Head of the Charles for four years in a row.

Harvard University, which won the national championship at Cincinnati last spring, was second in 15:43.94, followed by Navy in 15:46.17, UCLA in 15:50.82, and Northeastern University in 15:51.84.

The University of Wisconsin won the women's championship eights in 17:51.61. The 1980 Rowing Club of Massachusetts was second in 17:59.74.

St. Catharine's R.C. of Canada regained the lightweight eights title after a two-year lapse by edging Harvard. The Canadian boat covered the course in 16:00.92, Harvard in 16:09.15.

St. Catharines also captured the women's title for the second year in a row in 17:54.41. The Minnesota Boat Club was second in 18:26.30.

David Challinor, 68, of the Potommac B.C. of Washington won the veteran singles for the fourth consecutive year in 21:17.52. Karin Loewy, 63, of Philadelphia won the women's event in 27:45.88.

William Reimann of the host Cambridge Boat Club upset four-time champion John McGowan of the New York A.C. in winning the grand master singles in 21:01.35. McGowan finished in 21:02.08.

McGowan's wife, Carol, won the women's grand master singles in 28:59.45.

Michael Richardson-Bach of Weston won the men's club singles in 19:33.92,